Expanded gamut - when an idea's time has come

April 10, 2018, 6:00 am

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I enjoy researching the history of innovation.

Last week's post was the history of the creation of the board game Monopoly. It was a tale of innovation and deception; about good old capitalism at its best and at its worst. Today I will track the development of another innovation, but there is no deception and no villain in today's story. There is no moralistic message, just a practical message for would-be innovators.

So, mix up a Printer's Delight cocktail, and enjoy today's history lesson. For those not familiar with it, this drink is a combination of blue Curacao, Malbec, Yuengling, and Kahlua. The proportions are adjusted to match the appropriate color.

Try all 1,617 variations with the IT8 sampler!

The past few years, there has been a lot of hoopla about expanded gamut printing, which is to say, printing with inks beyond the standard four colors (cyan, magenta, yellow, and black). To the casual observer, one might conclude that this was a relatively recent idea. This is true... well... if one is willing to define recent in a more geologic sense.

Hallmark Cards

The earliest instance that I have found of expanded gamut printing dates all the way back to 1960 with a company called Hallmark Cards. If you are are not familiar with Hallmark, they invented the idea that you had to feel guilty about not sending a card to your mother on Mother's Day. I haven't found the original patent for the guilt thing, but it must have been filed somewhere around 1920.

Hallmark's unique printing problem is illustrated below. Greeting cards have a lot of pastel colors. These colors are often outside of the normal printing gamut. It is not always appreciated, but CMYK just can't get you highlights that are both very bright and highly saturated.

Karl Guyler (of Hallmark) said that Hallmark was in production with a six color process by 1962. The inks included fluorescent pink, yellow, and magenta. The system was so cool, that they had to give it a cool name that they trademarked: BigBox Color^TM. Although (as I mentioned before) Hallmark patented the guilt associated with their gilt, for some reason they did not patent this particular method of expanded gamut printing.

Why did this innovation happen? Hallmark had special niche needs that were not met by the existing technology.

Why didn't this innovation spread like wildfire? At the time, these were niche needs, and others didn't see a benefit.

Shoichi Shimada

The earliest patent I found on expanded gamut printing was from Shoichi Shimada of the Japanese company Dianippon Screen, filed in 1968. This patent describes a method where printing plates "are produced for reproducing color images with inks other than the standard inks …" They use three primary inks (cyan, magenta, and yellow), three secondary inks (for example, orange, green, and violet), along with black ink.

The diagram below shows in simplistic terms how the color separation is to work. Color space is divided into six pie slices. Actually, since color is three-dimensional, think of these as three apple slices. Each slice of the apple is assigned one of the process colors (CMY), one of the extra colors (in this case OGV), and black. The system determines which slice of apple the given color belongs in, and uses the appropriate inks for that apple slice to create the given color. 

Shimada-sam's color separation strategy

Shimada-san's patent mentions that printing of calicoes on fabric often uses a variety of non-standard inks to make images, but the color separation for this is "obtainable only by very complicated hand works [sic]". In patent parlance, printing of calicoes with special ink sets was admitted as prior art. To get a patent over prior art, one needs to demonstrate a novelty over the prior art which is non-obvious. One of the novelties in this patent is that they laid out an automated mechanism for replacing this very complicated hand works [sic].

Simple, easy to implement color separation technique

I was unsuccessful in finding out whether this invention was ever put to use. Google doesn't seem to know much about it. I have found precious little mention of the patent in my extensive search of technical papers on expanded gamut. I found the patent only through some pretty deep patent searching. The idea may have been actually turned into a product, but it certainly didn't become wildly successful.

Why did this innovation happen? According to the patent: "Such the special color inks [sic] are demanded frequently for the printing of color images which are difficult to produce by the combination of the standard inks."

Why didn't this innovation spread like wildfire? I can only guess, but it might be that the invention lacked a strong market driver. Yeah, it's nice to make more colorful images, but you can't build a better mousetrap until the world beats a path to your door.

Hang on to this thought, though. This patent describes something very similar to what we today call expanded gamut. The color separation is a bit different than what is done today. Currently, colors that are within the CMYK gamut are often printed with just CMYK, but otherwise, this looks a lot like what is done today.

Harald Küppers

Harald Küppers (often spelled either Kueppers or Keuppers, and rarely as kippers) developed a strategy for printing with more than CMYK, and filed for a patent in 1985. His method called for printing "… whereby the elemental surfaces which form the chromatic component are printed with a maximum of two of six chromatic printing inks, yellow, magenta-red, violet-blue, cyan blue, green and black…"

This deserves a bit of explanation. Kueppers' technique was not the traditional halftone technique as we all know and love. In his system, there is no overprinting of the halftone patterns of multiple inks. Instead, Kueppers divided the printed page into square cells, with each cell being divided into rectangular areas of up to four non-overlapping inks. Each rectangular cell is printed with certain rectangular areas of white and black -- the white area may be actually printed, or it may be the color of the substrate showing through. This gives the lightness. Each rectangular cell also is printed with up to two chromatic colors including yellow, magenta-red, violet-blue, cyan blue, and green.

The image below was taken from Kueppers' patent (4,812,899). It demonstrates the conversion of a color value (in this case described as a combination of violet, green, and orange) into a mosaic of printing inks. The colored box in the lower right corner is my own clarification of the box in his patent labelled Fig. 5c. Yeah, the colored box that looks like a Mondrian painting.

Keuppers' printing is a tiling of Mondrian blocks

Note that the little box labelled "S 25" is black (K 25). The German word for black is schwarz. In case you hadn't guessed, Kueppers lived in Germany.

If you squint real hard, this Mondrian of Kueppers tiles will look dark yellowish green

Anyone who has run a printing press will readily recognize that this technique is not practical for litho or flexo printing. Any small amount of misregistration will cause a color shift. For example, if the green ink were to be shifted a bit to the left, it would overlap with black. The color of the overlap would also be black, so misregister in that direction would cause a loss of green.

It is clear that Shimada-san's patent is more closely related to today's expanded gamut printing than Kueppers' patent. And yet, I have seen several references that claim that Kueppers' work is the forerunner of modern expanded gamut printing. Clearly that's wrong, since Shimada-san's invention not only predates Kueppers' work by almost 20 years, but Shimada-san's invention works a lot more like modern expanded gamut printing.

Why has history incorrectly attributed Kueppers with the invention of expanded gamut printing? I have several possible explanations:

1) Stigler’s Law of Eponymy: “No scientific discovery is named after its original discoverer.”

2) Kueppers' idea saw some market success. He produced a color matching book using his process, and apparently a bunch of these were sold. Hallmark's idea was forgotten since it was a niche solution to a different problem. Shimada-san's technique apparently did not create much hubbub. 

3) Kueppers' patent is a bit hard to understand. Much like Bob Dylan's lyrics, I think if Kueppers' expanded gamut printing were better understood, it would have gotten less credit. I readily admit to not understanding the patent the first 413 times I read it. I had been reading it with the assumption that it used normal halftone printing, so the diagram above (Fig. 5) was confusing. I assume that other print historians made the same mistake that I did. 

I didn't catch the idea of Kueppers' patent until I was reading through Kiran Deshpande's doctoral thesis, and saw his Mondrian diagram. Thank you, Kiran!

So, now my two innovation questions for the Kueppers approach to expanded gamut printing.

Why did this innovation happen? According to Kueppers' patent, he sought to solve the problem of moire patterns that are seen with conventional halftone printing, and he wanted solve the problem with conventional printing that "pure and luminous colors cannot be produced well." That is, he wanted to expand the gamut.

Why didn't this innovation spread like wildfire? The references below state that Kueppers' method languished because the color separations were manually intensive. I don't think that this is the case. The patent shows a scanner and a circuit for color separation. It is not necessary to have built an invention in order to get a patent, but it seems that the mechanics were fairly well developed when the patent was filed.

I think the more likely reason that the technique did not flourish is that, as stated before, it just was not practical for typical printing presses because of color shift due register.

Everything you thought you knew about the history of expanded gamut printing is wrong

Clearly, expanded gamut's time had not yet come. I'm getting tired now, so I will continue this in another blog post, which will be called the Heyday of Expanded Gamut Printing Patents. 

References

Bernasconi, Mathew, Color Printing Process and Product, US Patent 5,751,326, filed April 5, 1995

Boll, Harald, Color-to-colorant transformation for a seven ink process, Proc. SPIE 2170, Device-Independent Color Imaging, (15 April 1994)

Boll, Harold, and Scott Gregory, Color-to-ink transformation for extra-quarternary printing processes, US Patent 5,563,724, filed Oct 21, 1994

Cooper, Ted, Process for creating five to seven color separations used on a multicolor press, US Patent 5,687,300, filed March 27, 1995

Deshpande, Kiran, N-colour separation methods for accurate reproduction of spot colours, PhD thesis, University of the Arts London, May 2015

Guyler, Karl, Visualization of Expanded Printing Gamuts Using 3-Dimensional Convex Hulls, TAGA 2000

Herbert, Richard and Al DiBernando, Six-color process system, US Patent 5,734,800, filed Nov 29, 1994

Hutcheson, Don, Hi-Fi Color Growing Slowly, GATF 1999

http://www.hutchcolor.com/PDF/HiFiupdate98_2000_04.pdf

Küppers, Harald, Printing process where each incremental area is divided into a chromatic area and an achromatic area and wherein the achromatic areas are printed in black and white and the chromatic areas are printed in color subsections, US Patent 4,812,899, filed Jan 29, 1989

Küppers, Harald, Process for manufacturing systematic color tables or color charts for seven-color printing, and tables or charts produced by this process, US Patent 4,878,977, filed Nov. 7, 1985

Hamilton, Jim, High Fidelity Seven Ink Printing, Technical document from Linotype-Hell, 1994

http://www.greenharbor.com/LHTIfolder/lhti9405.pdf

Shimada, Shoichi, Apparatus for production of color separation records, US Patent 3,555,262, May 7, 1968

Viggiano, J A Stephen  and William J Hoagland, Colorant Selection for Six-Color Lithographic Printing, Proceedings of the IST/SID 1998 Color Imaging Conference, p 112 - 115

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Expanded gamut - when an idea's time has come, addendum

April 26, 2018, 6:00 am

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Welcome John the Math Guy blog fans. Today, you can color me embarrassed. 

Here is a quote from my recent post on the history of expanded gamut printing: "The earliest instance that I have found..." Did I get called out on my lack of scholarly research on that topic! Not just from one person, but from three people! With multiple examples that significantly predated my lousy excuse for research!

The Math Guy, suitably humiliated

Gary Field

The first person who took me to task was Gary Field, professor emeritus from Cal Poly. Being corrected is embarrassing, of course, but being corrected by Gary Field is almost an honor. I am not saying he has been in print for a long time, but before God carved the Ten Commandments into stone tablets, he hired Gary as a lithography consultant. Gary is known as the author of the printostorical book The Color Printing Revolution: Productivity! Creativity! Quality!, and is a co-author of Pioneers of Modern Offset Lithography.

In his first response, Gary traced expanded gamut 70 years further back than I did. Here is a response from Gary on one of my LinkedIn posts.

Expanded gamut printing goes way back to the early days of process color printing - the 1890s. If you can locate early editions of the Penrose Annual, you will find many beautiful examples. 

There were three reasons for employing extra colorants: poor purity process pigments, additivity failure, and proportionality failure. In the early days (pre stochastic screens) moire avoidance was a key constraint. I used to make 6-color separations in the early 60s with proportionality failure correction the objective. Light cyan and light magenta were the extra colors (today they use the same colors in photo-quality inkjet printers). Light and regular magenta (for example) were placed on the same screen angle and the tone scales adjusted such that each colorant provided the highest purity for its respective part of the tone scale.

I looked for information on the Penrose Annual. Wikipedia agrees with Gary. The Wikipedia article says: "Penrose Annuals remain the quintessential record for the development of mass media, advertising, photography, design and typography throughout the 20th century..." 

The cover from the second issue of Penrose Annual

So I read though a few issues. The second issue of the Penrose Annual (1896) had an article on the history of three-color printing which is prophetic in view of this blog post:

The three-color process had to undergo the same experiences and difficulties as every new invention. At first one man claimed to have invented quote a new thing, then several others arose and claimed the first right of invention for this; and at last everyone got to know that the new invention was nothing but the old thing known years and years ago, thus confirming the old proverb "there is nothing new under the sun."

(This may be true, but I believe that I was the one who first said this old proverb, I mean, ecclesiastically speaking.)

I did a rudimentary search of the early issues of the Penrose Annual. The first few had articles on printing with three colors. The earliest article I found that referred to more colors was an article comparing the three-color and four-color processes in the 1898 issue. I quote: "the litho printer is taught to produce his ten or twelve color print". Oh! I guess expanded gamut lithographic printing was commonplace in 1898!

Gary goes on to chastise me for my poor research techniques, and also for my prodigious collection of patents:

Most patents, frankly, are worthless. It is not that difficult to locate the "prior art" of some enterprising photolithographer (often in the Penrose Annual).

Of course, over the course of several emails back and forth, Gary felt the need to demonstrate some further prior art. He found a patent for expanded gamut photography that was filed in 1950 in Great Britain: Improvements relating to multicolour photographic reproduction, by Joseph Arthur Ball. I dunno how I managed to miss this one. Pretty lazy of me, really.

Apparently he felt the need to outdo himself -- I mean this is a competition, after all -- and played the trump card: Process of photomechanical reproduction of colors and the resultant article (Charles Zander) which was filed at the US Patent Office in 1905. This is a four-color photographic process, which may not sound all that impressive since printing uses four inks. But his process was with four chromatic pigments: magenta red, lemon yellow, emerald green, and ultramarine blue.

So. I concede. Gary won.

Robin Myers

As if this weren't enough, another good friend, Robin Myers, had his own commentary on my research:

Your latest post on wide gamut printing is very interesting, but it exposes a flaw in performing historical searches using the Internet alone. The Internet is a wide pool, but for historical information, mostly shallow.

Boy, have I been called out on the carpet!

Robin is an archeo-bibliophile and collector of old books. He thanked me for not calling him a pack rat. Robin is also the proprietor of Chromaxion, a repository of color information. If that were not enough, he is the author of SpectraShop, a color acquisition program that I have actually used.

After reading my recent blog, Robin pulled out his copy of Dictionary of Color, published in 1930 by Maerz and Paul. This book was one of many efforts that attempted to provide official definitions of color names by way of color patches. (Earlier color-naming books were from Albert Munsell (1915), Robert Ridgway (1912), Milton Bradley (1895), Johann Ferdinand Ritter von Schönfeld (1794), and A. Boogert (1692). Boy, that sounds like grist for a future blog post!)

Available to pack rats through Amazon

I should clarify the images above. The image on the left is a page of delightfully pretty color patches from the book that were printed with two different inks. The image at the right is from the facing page, with a grid, and names of some of the corresponding colors.

Here is what Robin had to say about Maerz and Paul:

After reading your article, I decided to check a copy of “Dictionary of Color” by Maerz and Paul, published in 1930. This book was printed using many more than the standard 4 colors. ... So the techniques of printing with expanded gamuts on press were known well before the 1960’s. I suspect that they were not widely employed for economic reasons.

The authors claimed, and indeed used, 8 chromatic inks and 8 achromatic inks. This I confirmed by spectral measurement with an i1Pro 2 and visual observation with a Beta Color Proofing Viewer II (modified to use white LED illumination). The charts were printed using 150 lpi screens (determined by a Screen Pattern Analyzer and Rescreening Key from RIT).

I was provided with spectra of the inks that were used, that clearly show eight different inks. Robin is nothing if not thorough.

We had an interesting discussion (not a surprise, our conversations are often interesting) about what constitutes expanded gamut printing. The world's oldest book with multi-color printing was the Manual of Calligraphy and Printing, which was first printed in China in 1633. The images were printed with up to ten different inks. Should we consider this gorgeous collection of prints to be expanded gamut printing? We decided "no". This book was block printed, and we decided that to qualify as expanded gamut, it must have halftones.

I could not find a copy of this from Amazon

Robin also dug up some real gems -- early books that showcased a lot of early printing beyond CMYK: A Half Century of Color by Louis Walton Sipley (1951), Practical Color Simplified by William J. Miskella1 (1928).

I guess this trounces the myth that Hallmark Cards invented the whole expanded gamut thing. Who started that silly myth, anyway!?!?

Larry Goldberg

The mention of the Beta Color Proofing Viewer leads us to the next person to expose my inadequacy in the field of the history of science, Larry Goldberg. Larry runs Beta Industries, which was mentioned by Robin. Note that this email was the second email that I received that mentioned a rat.

I thought I smelled a rat, or at least a fish.

Mr. Kippers (his pseudonym didn't fool me for a minute) color system reminded me of a system that I actually saw, and met the inventor thereof.

When there used to be a very good printing trade show in Long Beach, CA called the Gutenberg Festival a fellow came around with a sample of an additive color printing method.

It used fluorescent inks and a black keyline.  Newspapers, always famous for their print quality, could run cartoons in full additive color, and just keep running the black-only image if they ran out of dayglo ink.

The inks are quite opaque, as the substrate offers no benefit.  White was the result of tri-color adjacent bits.

The guy's name was WEAKLY or WEEKLY, but my  USPTO searches never produced a hit.  He also had a patent that he said was the ONLY one that used the term "Dick Tracy" in describing a wrist-worn electronic signalling device.  Little did he know the Apple Watch was just 30 years around the bend.

Larry eventually found the patent. Here is a link: Mosaic additive reflectance color display screen.

The Mosaic Screen Plate

I am going to explain Weekley patent, but lest one get confused, first I need to explain Larry's comment about the Kueppers patent. Kueppers' patent combined two interesting concepts. The first concept was about using more inks than just CMYK for printing. The second concept was about creating color my placing little color patches adjacent to one another, but not touching. This is known as additive printing. Larry was commenting that he remembered hearing about a patent for another process that used non-overlapping patches. He wasn't claiming that this invention had much to do with going beyond CMYK. (Although, Weekley did use fluorescent versions of CMY. Odd that he didn't mention fluorescent black ink.)

Weekley's patent was an improvement to a process that was invented in 1868, called the mosaic screen plate. This is an interesting bit of history and technology.

Ducos du Hauron was a pioneer in the field of color photography. In 1862, he invented the idea of the mosaic screen plate as a way to take color photographs using black and white film. This glass plate is a set of really tiny filters of red, green, and blue. The back side of this plate was covered with a normal photographic emulsion, containing silver halide, which would normally produce a black and white photograph.

Mosaic filter plate

(color scientist's conception)

When taking a picture, the emulsion was exposed from the front side, that is, through the filters. Thus, on the back side, there were areas where the emulsion had been exposed with only red light; others where the emulsion had been exposed by only green light, and still other areas where the emulsion had been exposed with only blue light. The individual areas were thus indicative of the amounts of red, green, and blue light in the image.

The emulsion on the plate was then developed with a positive process -- areas where light hit would be white, areas with no light would be black. When the developed plate was viewed (with the filters still intact) the intensity of the light reflected through the red, green, and blue filters would be in accordance with the amount of red, green, and blue light that was in the exposing image.

I was careful in my wording before. I said that du Hauron invented the idea of the mosaic screen plate, for which he was awarded a French patent in 1868. As you might imagine, those mosaic filters are kinda hard to build. Here is an interesting factoid about patents: you are not actually required to build the invention to get a patent. All you need to do is describe it in enough detail so that "one skilled in the art"could build it.

The first commercially successful implementation of du Hauron's invention didn't occur until 1903, with the Autochrome Lumière. The Lumière brothers figgered out how to make this mosaic screens. They sifted potato starch grains to a uniform, microscopic size. For the logophiles in the crowd, this process is known as elutriation. For the people who aren't really all that fanatical about words, the process is known as sifting.

One of the Lumiere brothers, proudly posing with the US version of their patent

They then dyed batches of the grains in each of the three primary colors. These grains were then mixed, and deposited, one layer deep, on a glass plate with black pitch between the particles. This mixture was pressed between glass to flatten out the grains to cover more area. Thus, they had a mosaic. It did not have a regular pattern as in my drawing above, but that didn't matter. Each grain was too tiny to see anyway. All that mattered is that the silver halide on the back side remained in register to the colored grains on the front side.

One problem with the mosaic screen plate was that the final film was rather dark. Imagine that the original exposure was with white light. The red pixels would all be bright red; the green pixels would be all green; the blue pixels would be bright blue.  But when viewed under white light, two-thirds of the light that hits the plate gets wasted. Any green or blue light what hits the red filter would get absorbed by the red filter. 

This is the problem that Weekley addressed through various methods. Fluorescent inks was part of that. I won't get into the rest.

Addendum to the Addendum

I want to give my sincere thanks to each of today's contestants of John Doesn't Know His Mosaic Filter Plate From a Hole in the Ground! All seriousness aside, I think this history stuff is pretty cool, and appreciate the additional information.

In order to at least partially redeem myself, I feel the need to challenge Weekley's comment about being the only patent with the term "Dick Tracy". I did a bit of searching and found a few that predated Weekley's patent. 

Telephonic unit with battery power auxilliaries, April 23, 1957

Wrist carried radio set, May 1, 1962

Method of manufacturing recording heads, November 19, 1968

Apparatus for forming artistic patterns, July 8, 1969

The dates listed are when the patents were granted, that is, published for all the world to see. Weekley's patent was filed in 1979, so he gosh darn shoulda known about these! Was that too harsh? Maybe I'm just jealous that none of my patents are cool enough to mention Dick Tracy.

The heyday of expanded gamut printing patents

May 8, 2018, 6:00 am

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In the previous installment of this series on the history of expanded gamut printing, I chronicled three times where augmenting CMYK with a few extra colors was independently invented. There was such an uproar to my post that I had to write an addendum to add all the examples that I had missed.

At Hallmark Cards, the technique served a niche need for that time and place. The work of Harald Kueppers seems to have found a different niche, and gained some attention, but it saw limited use. And the developments at Dainippon, while they were very similar to what we see today, have left little trace in the history books. All the examples cited by friends also wound up being niches.

Sad fact: expanded gamut did not go mainstream during this time period.

One of the commentators on my post commented a comment about the futility of doing patent searches to dig up history. So today, I look exclusively at the patent record. In this blog post, I look at a period of twelve months in 1994 and 1995. These 372 days rocked the world of CMYK printing to its the very foundations. You think I'm being overly melodramatic? Consider this: These 372 days saw not one, not two, not three, four, or five, not six, but seven filings for patents on expanded gamut printing. CMYK printing. World of CMYK printing, consider yourself rocked.

Expand my expanded gamut, baby!

Hutcheson, Du Pont, March 29, 1994

If one cyan print unit is good, then two must be better, right? And if you print with two cyan print units, why not two magenta, and two yellow, and two black? The idea is to give a double bump anywhere that you need more ink than a single print unit can provide. This was invented by the very modest Don Hutcheson, and marketed by Dupont under the name HyperColor. I guess someone vetoed the name HyperDon.

Don'cha just love the cute drawings in patents?

The technique can be considered an expanded gamut process, since it does expand the gamut. It just uses CMYK as the additional colors, instead of OGV or some other collection.

Some of my readers may have met Don Hutcheson. He is still in the business, and is actually still working on this project. Idealliance's XCMYK project is a way to expand the gamut by pushing the standard CMYK to higher densities. After 24 years, one would hope that he will be making some progress soon.

A note on patents: Patents generally have a section at the beginning that describes the background of the invention or alternately, the prior art, that is, the existing stuff related to the new stuff being invented. The title prior art is actually shorthand for prior art bashing, since this section usually highlights the deficiencies of what is already out there. The prior art section is followed by an obligatory section  where the inventor explicitly states the purpose of the invention. This section is obligatory because patents have to be for something useful. I found that out the hard way when I tried to patent a wind tunnel with left-handed ear flaps!

What was the purpose for this (I mean Don's) invention? A quote from the patent: "... it is believed to be advantageous to provide a method for extending the color printing density range of a printing device without introducing special or non-process printing inks or unconventional pre-press proofing systems..."

Plettinck and Van de Capelle, Barco, April 29, 1994

Technically, this is not a printing method. It is a way to convert one color separation (based on CMYK) into another separation based on non-standard inks. What do they mean by "non-standard"? Here is an example from the patent:

For example, a chocolate manufacturer will prefer an ink set wherein brown ink plays a more dominant part.... So for example PANTONE (registered trademark) red, process yellow, and PANTONE brown form a set of non-standard inks that are used for printing packaging material for chocolate.

Reading the patent makes my mouth water!

Well... ok... maybe this isn't really expanding the gamut, although it could. I just couldn't pass up a patent that talked about chocolate. Those of you who are chocolate fanatics will understand.

What is the purpose of this invention? "The object of the invention is to provide a method for generating printing data wherein the second colour separation is determined in a more efficient and non-empirical way and a result is that the printing quality remains unchanged or is even increased."

Eder and Maerz, Eder Repros Offset Repro GMBH, May 19, 1994

This patent is in German, so I admit to not having read it in full. Well, actually, I didn't read any of it. But, I can tell you that Eder has been described by Anastasios Politis as: "One  of  the  most  significant  pioneers  in  processing  CMYK  +  x  colors...". I also know that Linotype-Hell marketed the Eder software under the name Eder MCS (Multi-Color Separation). More on that in a bit...

The company Eder still exists, and is doing software under the byline "product communication in the digital age".

Printing of the King Eider duck may benefit from ederMCS color separation

What was the purpose of the invention? I did some OCR on images from the pdf of the patent, and translated the German text into English: "It is therefore an object of the invention to provide a method for creating a color print image, with the help of which create high-brilliance color images, the required printing effort is reduced compared to the seven-color printing."

What is the purpose of me asking that question all the time? Please be patient. I am actually going somewhere with this. Suffice it to say that, so far, making prettier pictures has been the main goal so far.

Boll and Gregory, Eastman Kodak, October 21, 1994

One of the many things I like about writing patents is that the patent writer is allowed to be his or her own lexicographer. That means they can make up words! The title of this patent contains the word extra-quarternary, which I take to mean "beyond four".

Some comments on this uber-cool word. First, Harold Boll told me in an email: "I longingly love that word too, mainly because it should have been in the title of my first patent!" In the body of his patent, he used the word extra-quaternary. Due to a clerical error, an r was added to the word: extra-quarternary. 

Yoko was an extra-quaternary

Second comment on the word: several writers have used the term extra-trinary to connote expanded gamut printing. This is just plain wrong!

Kodak first got their feet wet working on a profile for Pantone's expanded gamut product, Hexachrome. More on Hexachrome later... 

Kodak had at least one major customer for their software product, Hallmark Cards. If you remember all the way back to the first blog post in this series, you will recall that Hallmark was big into expanding their gamut in the 60's.

I'm getting ahead of myself a bit here, but Kodak introduced an expanded gamut product called Spotless in 2011, 17 years after the Boll and Gregory patent. It is likely that there is not direct connection between the work of Harold and Spotless. Why would Kodak jump back into the expanded gamut ballpark? Hang onto that thought. I will come back to it.

What was the purpose of this invention? "It is another object of the present invention that it is uniquely capable of exploiting all of the attainable color gamut afforded by an n-ink (n>4) printing process and thereby achieves maximum colorfulness for rendered colors."

Maximum colorfulness... yum.

Herbert and DiBernardo, Pantone, November 29, 1994

Everyone in the print industry knows of Pantone. Lawrence Herbert is the guy who started Pantone. His son, Richard Herbert, took over the reigns. Lawrence and Al DiBernardo are the guys who invented Hexchrome, which was perhaps the most well-known of the mid 1990s commercial offerings for expanded gamut printing.

This system uses orange and green as the additional colors (there is no additional blue or violet ink). They wanted to keep the number of inks down to six, so as to make it usable on more presses. The ink set also includes richer CMYK inks, and some of the inks are fluorescent so as to make them more vibrant.

One of the things that distinguished Hexachrome is that they had a special fandeck for the Hexachrome colors. These guides had all the colors in their regular book, but with one difference. The regular Pantone guides have a recipe for how to mix each color in a bucket of ink. The Hexchrome guides have a recipe for how to mix halftones on press to make the color.

 Still available on ebay

If the fan deck of expanded gamut colors came from any other company, I would say that this was a brilliant marketing move. It certainly raised the awareness of the product to have a physical sample of the system. But since Pantone was kinda in the business of making fan decks, it wasn't so much brilliant as it was obvious.

What is the purpose of this invention? The first few words of the summary are: "A printing system for high fidelity printing of an image is provided..." 

According to the patent, Hexachrome is all abut making high fidelity colors. But (important point here for my narrative) the Hexachrome book really can't be used to make pictures.  

Seinfeld's 100th episode, February 2, 1995

The 100th episode of Seinfeld aired during the 372 days that rocked the world of CMYK printing. Coincidence?

Jerry Seinfeld has yet to comment
on his alleged links to expanded gamut printing 

Cooper, Linotype-Hell, March 27, 1995

This patent is a two-step process. First the CMYK separation is created, and then a correction is determined. This is all pretty obvious when looking at the diagram below from the patent.

The patent office desperately needs a service for
colorizing gorgeous drawing from old patents

Linotype-Hell released this as HiFi Color 3000 in 1994. In 1995, they announced that they would be selling the ederMCS package. It would have been interesting to have been a fly on the wall for the discussions they had about switching over to someone else's product.

What is the purpose for this invention?  I will skip the patent, and go to a press release for High Fidelity Color Printing:

Why would anyone want to print seven inks?

    • Seven inks can print a larger color gamut which includes colors that the four process color inks cannot achieve.

    • Seven inks can achieve a brighter color appearance and improved modulation of color.

    • Seven inks allow closer color matches to the original.

    • Printing with seven inks produces cleaner reds, greens, and blues.

Here is an interesting quote from the patent: "Spot colors are not considered in this application." Hang onto that thought. I will get back to it. Really. I am getting to something.

Bernasconi, Opaltone, April 5, 1995

Mathew Bernasconi developed a system of expanded gamut which uses CMYK+RGB. This is one of the few systems patented in the heyday of expanded gamut printing patents that has survived. This patent covers a device which scans a photograph and determines a set of color separations. Conceptually, there are two scans. The first scan is that of a traditional scanner, where a CMYK separation is done. The second scan creates a separation for the expanded inks to make up for the limitations of the first separation.

One difference between this patent and the others is that the extra-quaternary colors are preferably red, green, and blue instead of orange, green, and violet. Bernasconi explains the use of red over orange,

Orange is not a primary color, it’s a secondary (i.e mixed from red & green light). Therefore using orange ink in an expanded system actually restricts the color gamut. A red primary mixed with a yellow primary creates pure orange (see overprint image below) thus expanding the gamut whereby the red primary is also mixed with magenta to create “scarlet” reds. The hue angle difference between 100% overprint (R+Y) & (R+M) should be >30º. This hue angle difference cannot be achieved with 100%  (O+Y) & (O+M) because the orange is too yellow from the outset.

This is not the NBC peacock

Just in case you are getting a bit confused about which set of colors are being used as primaries, I provide the comparison in the image below. Which one is correct? The concept of primaries is based on RGB color theory, which is a simplification of color science. So, primaries are not really defined in color science. If, however, you seek your primaries based on color engineering, then the correct primaries are whatever set of pigments give you the biggest gamut. Finally, if you are a color practitioner, then the correct primaries are the ones that get you the colors that you want.

Comparison of the chosen ink sets

Another note on patents in general: the body of any patent describes specific embodiments of the invention. In the case of Bernasconi's patent, the addition of red, green, and blue inks to CMY is an embodiment. But the teeth of a patent is in the claims. The claims are generally much broader, covering many different embodiments. In this case, the first claim refers to "a plurality of data channels", instead of listing a specific set of inks. This means that the Opaltone patent could cover CMY+RGB (the preferred embodiment), or it could cover CMYK+OGV or RGB+CMYK.

In a much later patent (2011), Bernasconi described a CMY+RGB variation on this invention. Instead of using black ink, this system mixes red, green, and blue inks to make black. In this way, expanded gamut printing can be done on a six color press.

What was the purpose for this invention? "... saturated colours such as deep reds, greens and blues cannot be reproduced satisfactorily due to the limited print range of four colour process."

One more expanded gamut effort

Mark Mazur acquainted me with another expanded gamut effort in this time frame. He says that it was the first product in the packaging industry that allowed the user to select his own set of pigments.

The company is called Specialcolor. According to their website, they started selling expanded gamut color separation software (under the name ICISS) in November of 1995. This is just after the 373 days that shook the very foundations of the CMYK world, but I would argue that, had Glynn Hartley decided to file a patent, it would have been in the critical time period.

I did search for patents from Glynn. Couldn't find any in the US or the European database. His website doesn't list any patents, so I am guessing he never filed. That's not to say that he didn't invent anything that was patentable. I think it's a pretty good bet that there was something is this effort that would be inventive enough to get a few claims in a patent.

So what happened?

In 1991, Don Carli made a bold prediction "High Fidelity methodologies ... Represent a revenue opportunity potentially accounting for as much as 15 - 20% of the $150 billion dollar world-wide color printing market by the end of the decade." Speaking of cool made-up words, I should mention that Don Carli coined the phrase HiFi printing. I also remember hearing him refer to stochastic screening as sarcastic screening. Love the guy.

These predictions were enabled by technology in the mid 1990s. Back in the old days, the thing that made plates was a combination scanner (to scan the films), computer (digital or analog, to do the math for color conversion and screening, and platesetter (to make the physical plates). This is a pretty closed system. Only a few engineers really got a chance to play with the cool stuff inside. This changed in the early 1990s.

Apple provided affordable workstations that could play with images before they went to plate -- desktop publishing. In 1994, Creo introduced the first Computer To Plate (CTP) system. With these two pieces, a larger group of engineers could play with the way color is separated, and then make plates.

Gary Field points to another necessary technology that enabled the Heyday of Expanded Gamut Printing Patents: stochastic screening, AKA FM screening. When additional inks are added to CMYK, moire patterns show up. Icky, objectionable moire patterns. FM screening is a way to avoid these icky, objectionable moire patterns. Now, FM screening goes way back to 1976, but Gary argues that "it wasn't until the introduction of Agfa's CristalRaster in 1993, that this technology became suitable for high quality work."

Thus, desktop publishing, CTP, and FM screening were the final enablers that made it possible for engineers to scan in image files, play with them on a computer with enough horsepower to do interesting stuff, send out the files to have plates made, and use those plates for high quality printing. The playground for innovation was opened.

By the late 1990s, we had all the technology in place from multiple vendors for expanded gamut printing. Separation software was available from Kodak, eder, Opaltone, ICISS, and Pantone. Inks were available through Pantone or Opaltone, or from your local ink vendor. Even Adobe jumped on the bandwagon. Postscript 3, which became available in 1997, included support for HiFi color.

Look out!! The expanded gamut ink train is coming through!

But...

Don Hutcheson wrote a "state-of-the-market" article for GATF World in 1999. His first sentence: "Despite a splashy introduction in the early 1990's, HiFi color printing has grown very little in the last five years."

Hexachrome was well known, but was it a commercial success? It was estimated in 1999 (Hutcheson's article) that Hexachrome was in use by only a few hundred printers. Bear in mind that at this time, there were tens of thousands of printers. Another article (from Glynn Hartley) said in 1999 that "there is a perceived low take up of Hexachrome".

In the same article about Glynn, he reported that there were "over 100 ICISS users currently operating in the UK." Maybe the software sold for the equivalent of $1000 a copy? I would call this a moderately successful small business. I don't want to appear to disparage him, but this is still a small business.

Hexachrome was discontinued in 2008, but Opaltone is also still around. They have their niche in the digital printing market. But they are not a huge company. ICISS is also still around today, but I don't see 100 employees on LinkedIn.

So what happened?

Expanded gamut was showing so much promise. Why didn't it fulfill the hype and become the default printing technology?

Here is an adage which is important to developers of new products: People are generally not willing to pay more for higher quality. There may be niches where the extra cost is justified, but if you want a product to hit prime time, look for ways to make it cheaper. Better yet, look for ways that it can save your customer money.

Adding a few more inks may make prettier pictures, but it will cost more. Prettier, but more expensive pictures are definitely in the niche bucket.

Kevin Bourquin has pointed to another issue that held expanded gamut back in the 90s: "I think the problem in 1994 was that while there were patents about how to do separations and some software to help, it was not well integrated into the production workflows. This made it cumbersome for companies to keep streamlined workflows." Having software to do the color separation is super cool, but you also have to be able to design, create a proof, do the RIP (with FM screening), set up profiles and plate curves, and do process control at the press side. Finding a collection of software together from multiple vendors to do something new can be a challenge.

So what finally happened?

In 2013 Mark Mazur conducted a survey that estimated that 10% to 20% of printers in the flexo world were using extended gamut. Don Carli's prediction came true, but about 15 years later than he predicted, and only within one segment of the print market.

More recently, the percentage has been soaring. Dawn Connell (Brand Marketing of Snyder’s Lance, who own Snyder’s pretzels, Jays, Kettle, Pop Secret, and Archway, to name a few) spoke at the Flexographic Technical Association forum in spring of 2016. In her presentation she said that 85% of their work is expanded gamut. 

In 2016, Kevin Bourquin of Cyber Graphics told me that they have 5500 SKUs separated for expanded gamut. I just checked back with him. As of April 30, 2018, the number is 8615. I should also mention that Kevin spoke on expanded gamut at the FTA Forum conference in Indianapolis on May 7, 2018. (Rumor has it that he mentioned my blog.)

Kevin's presentation isn't the only presentation on expanded gamut at a high profile conference. I just got news that Mike Strickler will be speaking on the same topic at another big print conference at the end of September / beginning of October. This won't be just a quick twenty minute thingie. He has a whole seminar. Smart guy, this Mike fellow. We taught each other everything we know.

Having guys with these credentials... speaking at such prestigious conferences... How can you say that expanded gamut is not a big thing now?!??!

It's not about pretty pictures

Why this huge recurrence?

Kevin points to another enabling technology: "But the first real tipping point was about 2004. Digital flexo plate had gotten a lot better and could print somewhat consistent if you tightly controlled to process. At the same time Esko and Kodak at the Drupa show, committed development resources to ingrate these tools into the workflows that people used to push files." As you can tell, Kevin is big on this whole workflow thing.

Mark and Kevin both pointed to one major snack food company that was an early adopter. Frito Lay was aggressively pushing to drive cost down and quality up. It's tough to meet both of those goals without doing some retooling.

Feeling a bit peckish?

But enabling technology doesn't necessarily translate into market success. Companies need a reason to want to invest in change. According to Mark Samworth of Esko, "The number one way to reduce costs in packaging printing is to reduce the use of custom spot colors." He has no idea whether this is true or not, but he did say I could quote him on this.

It probably seems like ages ago that I mentioned that Kodak jumped back into the expanded gamut in 2011 market with Spotless. (Scroll back if you don't remember.) The name is pretty clever, really. The word means clean, but literally, it means without spots. The pun refers to the fact that expanded gamut printing can be used to replace the icky-dirty practice of spot color printing. Roughly 90% of the Pantone book of spot colors can be printed as a halftone of CMYKOGV.

This saves money. In an old-school print shop, the printer would print the first job of the day with CMYK plus a couple of spot colors. To switch over for the second job, the print units with the spot colors need to be cleaned out to put in a few other spot colors. Cleaning out the print units takes time. Furthermore, the left-over ink can't be just poured down the drain. It has to be stored in buckets for future jobs. I have seen shops that have invested a lot of money just in shelving units to store leftovers. 

Cleaning up after a spot color ink party takes time

With expanded gamut printing, the mixing of inks to make spot colors occurs not in the ink kitchen in buckets, but rather, on the press with halftone dots. Hence, there is no need to clean out the CMYKOGV print units between jobs.

I spoke with Steve Balschi (who is a prepress guy at PrintPak, huge packaging printer), who said that they have plants where all they print is expanded gamut. Steve went on to explain that they had three type of expanded gamut jobs: 1) jobs where only spot colors are printed expanded gamut, and images are left CMYK, 2) jobs where spot colors and images are converted to expanded gamut, and 3) jobs that are a mixture. Whenever possible, they do not convert the images. But why would they want to? They're trying to match an image that was printed with CMYK. The best way to do that is to print CMYK. This underscores my point that it ain't about prettier images.

A further savings comes from the ability to gang jobs, as illustrated in the image below. Multiple related products are printed on the same press as one run, rather than as multiple smaller runs. The same amount of printing, but with only one make ready.

Choco Lotta is one of my biggest sources of snack foods

Spot color replacement is big not only in and of itself, but it enables this gang printing which is like, way big. John Elleman commented on LinkedIn: "[Spot color replacement] is most commonly used for creating flavor/form coding across multiple packages allowing gang printing all on one form versus sequential printing with spot colors, which increases cost for extra printing plates and change over time on press." Kevin Bourquin had a similar comment: "The true benefit is the economics involved in running multiple jobs in combo after replacing all the spot colors."

When has an idea's time come?

Thanks for sticking it out through this long and boring dissertation about the history of expanded gamut printing. We finally get to the moral of this series of blog posts.

In the previous installment (and the addendum) we see that just having a clever idea doesn't make you a millionaire. Unless of course that clever idea is to marry into a hugely wealthy family. In the first part of this blog post we see that a clever idea with a slick implementation is also not necessarily a ticket to the Filthy Rich Club. 

Here is the moral: An idea's time comes when the idea meets up with both the enabling technology and the need. I put that in italics to remind people to quote me on this. The idea of printing with inks in addition to CMYK is a clever idea. Desktop publishing, FM screening, high quality plates, and a full workflow solution are all enabling technologies. Replacement of spot colors was the need that made this idea worthwhile.

When an idea's time has come

Acknowledgements

Normally, I just make stuff up for my blogs. In this case, I thought I might try something a little different. I would like to thank the following folks for making sure my facts were as factual as possible: Don Hutcheson, Mark Mazur, Steve Balschi, Kevin Bourquin, Gary Field, Robin Myers, Mike Strickler, and Mathew Bernasconi.

References

Bernasconi, Color Printing Process and Product, US Patent #5,751,326, filed April 5, 1995

Bernasconi, Color separation and reproduction method to control a printing process, US Patent 8,064,112, filed November 22, 2011

Boll and Gregory, Color-to-ink  transformation for extra-quarternary printing processes, US Patent 5,563,724, filed October 21, 1994

Carli, Don, and L. Mills Davis, High Fidelity Color Rendering and Reproduction, TAGA 1991

Cooper, Process for creating five to seven color separations used on a multicolor press, US Patent 5,687,300, filed March 27, 1995

Eder and Maerz, Producing colour printed image from scanner, German Patent #4,417,449, filed November 23, 1995

Hartley, Glynn, PrintWeek, Bespoke HiFi provides value added market for print films, December 10, 1999

Herbert and DiBernardo, Six-color process system, US Patent 5,734,800, filed November 29, 1994

Hutcheson, Extended density color printing, US Patent 5,528,377, filed March 29, 1994

Hutcheson, Dom, HiFi Color Growing Slowly, GATF World magazine, 1999

Linotype-Hell, High Fidelity Seven Ink Printing, 1994
http://www.greenharbor.com/LHTIfolder/lhti9405.pdf

Plettinck and Van de Capelle, Method and a device for generating printing data in a color space defined for non-standard inks, US Patent 5,689,349, filed April 29, 1994

Politis, Anastasios, et al., Extended Gamut Printing: A review on developments and trends, 1st International Printing Technologies Symposium (PrintInstanbul 2015)

Wolf, Kurt, PS imagesetter: a reasonably priced entry with the Linotronic Mark series, 1995
http://xmedia.biz/home/page.aspx?page_id=550&archive_type_id=92&person=0&categories=&archive_id=2981&from=611&keyword=

Do you remember a logo?

May 17, 2018, 7:21 am

≫ Next: How well do we remember color?

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I stumbled across a quote the other day that I found interesting. This was on the Coca-Cola website:

"There is no Pantone color for Coca-Cola red, but when you see it, you know it."

Ah! To be tanning under the Coke Red Sun!

This sounds like one of those factoids that everyone knows is true, so nobody would be crazy enough to actually test it. Well, guess what? I know a few crazy people. In fact, one of my best friends, Eddy Hagen, has recently tested this very thing with an online test: how well can you pick out Coke red?

(As an aside, here is the process for joining the John the Math Guy's Best Friend Club: Connect with me on social media. Contact me somehow or other with a message that does not contain the phrase "John the Math Guy is a doofus." Then you're in. If you just want to get on my email list, then send an email to john@johnthemathguy.com to subscribe.)

There are two tests in Eddy's blog. In the first test, Eddy tests your short-term color memory . You are shown a color, and then asked to pick it out of a line-up later. That one is kind of a warm-up to the real test. In the second test, he shows you a bunch of colors and asks you to pick out Coke red.

Do people know Coke red when they see it, as the Coca-Cole website suggests? He shares the results in another blog post. I don't wanna give anything away, but the title of this post is You can’t correctly remember an iconic color, not even Coca-Cola red.

Which one makes you thirsty?

Who is right??!?!? Let's get to the bottom of this!

Brand color is important

Brand colors are important, especially if you have a brand to sell. Here is what Axel Kling (Print Quality Assurance Manager for Coke) has to say about the importance of brand colors:

In today’s marketplace of unlimited beverage choices, a brand’s first point of contact is most likely to be at the point of purchase. And how well your product stands out on shelf could determine whether it’s put in the shopping cart or left behind.

I know most of my readers have private chefs who do their grocery shopping, but imagine if you will, being in the snack aisle of a grocery. You are trying to find your favorite bran cereal with raisins. Just reading that line, I'm gonna guess that you're thinking "purple". Am I right??! Of course, the image below wasn't any clue.

When I am old, I shall eat cereal out of purple boxes

The bran owners of the various raisin brands have trained their cereal boxes to be distinctive colors so that they can jump off the shelf into your shopping cart. And lets, face it. Nothing says "raisin bran demographic" quite like the color purple.

This is an aside, but how can Kellog's and Post and Trader Joe's and Total and John the Math Guy Breakfast Foods all use the name Raisin Bran? Interesting trademark factoid: The Skinner Manufacturing Company was the first to sell raisin bran, back in 1926. It trademarked the name, but in 1944, the Supreme Court rescinded the trademark, saying that you can't trademark a simple description of a product.

Speaking of trademarks, the color purple, and brand colors ... In 2004 Cadbury applied for a British trademark for the color purple (Pantone 2685C)  "applied to the whole visible surface, or being the predominant colour applied to the whole visible surface, of the packaging of the goods."Nestle objected, and their application was denied. It seems you kinda have to have a mark, if you want to have it trademarked. But, this trademark application in 2004 was a revision of an earlier trademark from 1995, which is still in force, at least until Nestle contests that trademark. 

Imagine my surprise when I found out that the chocolate wasn't purple!

This is in the UK. I apologize in advance to my British friends and enemies, but I'm not all that excited about British law. I mean, back in 1492, we fought the Spanish-American war to get away from having to follow your laws about tacks in our tea. What about US trademark law and colors?

I read up a bit on Wikipedia about color trademarks. In the US, you can trademark a color so long as it serves no other purpose other than to distinguish your product. So, Johnson & Johnson can trademark the name Band Aid, but not the color, since that serves as camouflage on certain people's skin.

There are a number of colors that are trademarked in the US, as shown in the image below. I compiled these from the Wikipedia article and the Business Insider article Can You Identify These 12 Brands By Their Trademarked Colors Alone?

I am gonna conclude that at the very least, brand owners think that brand colors are important.

It's not just about being able to find your favorite cereal

Color is about brand recognition, It helps you find a specific product within a dazzling array of colors. But the prevailing wisdom is that it also communicates something about a product. Red universally means romance or hookers, except when it's used on a fire truck or a stop sign. And of course, it doesn't mean romance if you are in China, where red signifies joy and luck. Or on one of my earlier blog posts where I decided it just signifies excitement, which explains why double-decker buses are red. But trust me. The meaning of a color is universal and unambiguous.

John spent the better part of an afternoon looking for his cereal

I have heard several presentations at conferences where the speaker says something like "color accounts for 86.3% of our buying decisions". As a math guy, I know that 95.4% of all statistics are made up, so, is there any definitive research behind the importance of brand color? Or is this just one of those statistics that gets quoted enough so that it becomes established fact?

Here is a quote from Daivata Patil that sounds authoritative:

Color is ubiquitous and is a source of information. People make up their minds within 90 seconds of their initial interactions with either people or products. About 62‐90 percent of the assessment is based on colors alone. 

Authoritative, with numbers and everything. But the article does not describe how these numbers were determined or even give a reference to where they came from. Hmmm.... urban legend?

Here is similar quote from Axel's presentation. Remember Axel? The color guy with Coke? He attributes this quote to Jill Morton's Color Matters website. Both attribute it to Loyola University.

Color increases brand recognition by up to 80%. 

I googled this quote to try to find a link to the actual study. Note that I put quotes around the words so that Google knew that I was looking for those exact words in that order. Goggle told me there were "About 2,170,000 results"! I admit to not reading through them all. I looked at the first ten hits, trying to find the title or author of the study, or maybe a link. All of them mention Loyola, and several of the web pages reference Jill Morton. None of them give any more information about the study.

Time for an infamous John the Math Guy tirade. This is not Science. I'm not saying that I have reason to doubt the statement, or that the various places that provide this quote are required to track down and report the original source. It's just that, for me, I would like to assess the strength of the argument. Was this an undergrad student who made up the numbers the night before the term paper was due? A professor who assembled twenty students for a little test? Or was this a master's thesis with hundreds of volunteers following a rigid experimental protocol?

Gregory Ciotti expresses my concern a bit more emphatically than wishy-washy me:

Most of today's conversations on colors and persuasion consist of hunches, anecdotal evidence and advertisers blowing smoke about "colors and the mind."

Getting back to the topic

Let me take a minute to try to remember where I was going with all of this. Oh yeah. Eddy Hagen's experiment about Coke red recognition.

Eddy's online experiment carefully explains the methodology and the results. It's Science, but I'm not gonna claim that Eddy's online experiment is good solid Science, and I don't think Eddy would either. He acknowledges that not all monitors are calibrated, and surveys where the participants are self-selected are a bit less rigorous that random selection. It could be that zealous PepsiCo employees deliberately failed the test to discredit their competitor. Or it could be that some of the individuals clicked at random just cuz it was late at night and they were waiting for the pizza guy to arrive.

Signs.com did another test of people's ability to recall brand logos. They brought in 156 people, and had them draw the logos of ten well-known companies from memory. This involved recalling not only color, but the shape and text of the logo.

Can you draw these from memory?

They have some stats on various aspects of the logos, but I did my own counting. I looking only at whether they got all the right colors, without adding extraneous ones. The results below are not all that fabulous, especially for multi-colored logos.

Company	Correct	Colors
7-Eleven	14%	Green, Orange, Red
Burger King	20%	Blue, Orange, Red
Foot Locker	38%	Black, Red
Walmart	49%	Blue, Yellow
Dominos	53%	Blue, Red
Starbucks	53%	Green
Ikea	56%	Blue, Yellow
Apple	72%	Black
Target	84%	Red
Adidas	92%	Black

I will point out that I was rather lenient about allowing different shades of the correct color. I allowed an orange flavored yellow to count as a yellow, or for Ikea blue to be too light or too dark. The image below shows the variation in color for Satyrbucks, which uses only green in the logo.

156 guesses at Starbucks green

At the far left, you see all 156 logos as drawn by the participants in the survey. (You can see a full sized version of this on Signs.com website.) In the middle drawing, I pulled all of the green pixels from each drawing, and averaged them together to show the green that the participant chose. At the far right, I show the 21 contestants that came within 10 DE2000 of the true Starbucks green. For reference, a common tolerance for commercial printing a color is 3.0 DE2000. Only two people out of the 156 participants were able to create a color from memory that would have been deemed acceptable printing of that logo.

Caveats...

I have made the assumption that there was an unbroken chain of proper color management throughout this process. If I had to put money on that, I would say that I would prefer to not put money on that. I don't say that to disparage Signs.com at all. I just know that the bar for rigor in Science is pretty high. But, looking at the middle image above... I rather doubt that any deficiencies in the rigor of this test could have caused that much variation in color.

Another caveat is in the interpretation of the results. This is a test of the participant's ability to recall the proper color from memory (as in Eddy's Coke red test), but also a test of the participant's ability to reproduce that color using the software provided. So, the logo drawing test is harder than the task of trying to find your favorite raisin bran. 

Pondering

Eddy provided me with an interesting anecdote: "To put that unique Coke red in perspective: in the LinkedIn ‘Printing Production Professionals’ one of the printers that works for Coca-Cola shared that in the X-mas edition, the Coke red is slightly darker… (which I checked in my collection of Coke cans and it is correct) So if color is soooooo important, how does this different Coke red impact sales?"

I'm still kinda pondering why Eddy has a Coke can collection... but these two experiments beg the question about how precisely a brand color needs to be defined. Both experiments are well above the level of urban legend expressed by the statement "Color increases brand recognition by up to 80%". But neither experiment quite fulfills the high bar of rigor required to be accepted as peer-reviewed Science with a capital S. I don't expect to see either in the next edition of Color Research and Application.

But, the two experiments are suggestive, and that suggestion is a contradiction between the brand owner's expectations of what is needed and the psycho-physics of the color that we see.

In the next installment in this series, I will take a closer look at the Science that has been done, especially the Science having to do with our memory of colors. If you want a bit of a foretaste, look through the references below. I am going to pretend to have digested them in the next blog post.

References

Bae, G. L., M. Olkkonen, S. Allred, and J. Flombaum, Why some colors appear more memorable than others: A model combining categories and particulars in color working memory, J Exp Psychol Gen. 2015 Aug;144(4):744-63

Belcher, Teri, and Kevin Harvey, The Influence of Color, ANTEC 2007

Bartleson, C. J., Memory Colors of Familiar Objects, Journal of the Optical Society of America, Vol 50, No 1, Jan 1960

Burnham, Robert W., and Joyce Clark, A Color Memory Test, Journal of the Optical Society of America, Vol 44, No 8, Aug 1954

Ciotti, Gregory, The Psychology of Color in Marketing and Branding
https://www.entrepreneur.com/article/233843

Cunningham, Meagan, The Value of Color Research in Brand Strategy, Open Journal of Social Sciences, 2017, 5, 186-196

Elliot, Andrew J., Color and psychological functioning: a review of theoretical and empirical work, Frontiers in Psychology, April 2015, Vol 6, Article 368

Goguen, Kate, The Influence of color on purchasing decisions related to product design, Master's Thesis, Rochester Institute of Technology, Feb 20, 2012

Javed, Saad Ahmed and Sara Javed, The impact of product’s packaging color on customers’ buying preferences under time pressure, Marketing and Branding Research 2(2015) 4-14

Kling, Axel, The Importance of Color Management for a Consumer Product Company, Printing Industries of America Color Management Conference, 2011

Patil, Daivata, Coloring consumer`s psychology using different shades the role of perception of colors by consumers in consumer decision making process: a micro study of select departmental stores in Mumbai city, India, Journal of Business and Retail Management Research (JBRMR) Vol 7 Issue 1 October 2012

Mohebbi, Behzad, The art of packaging: An investigation into the role of color in packaging, marketing, and branding, International Journal of Organizational Leadership 3(2014) 92-102

Morton, Jill, Color & Branding, Color Matters
https://www.colormatters.com/component/content/article/62-color-a-marketing/240-color-a-branding

Satyendra Singh, Impact of color on marketing, Management Decision, 2006, Vol. 44 Issue: 6, pp.783-789

How well do we remember color?

May 30, 2018, 4:44 pm

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In a previous (and highly entertaining) blog post, I reviewed two studies that tested people on brand color recognition. The studies were not peer-reviewed, Nobel prize winning efforts, but enough effort was put into them for me to find the results suggestive. I don't mean that in a salacious way; I do mean that the experiments suggest that our recognition of brand colors is not as good as we might think it is.

The sight of Starbucks periwinkle makes me thirsty

In today's post, I will take a dive into what peer reviewed Science has to say on the matter, specifically on the topic of how accurately we remember colors.

What I didn't study

There are a lot of stones in this field, and I left a lot of them unturned. Here are some exciting topics that I skipped over...

Color and emotion - This is a big field. It would be cool to really dig into how color effects us emotionally. I would love to separate the wheat from the chaff (valid research from pontification). The paper by Yu et al. Looks like it would be fascinating. But, I didn't really look at it for this blog post.

Color and emotion and brands - Another mondo interesting study would be to look at our emotional reaction to the color of a box of cornflakes. Presumably, there is an ideal corn flake box color that will seduce the unwary buyer into filling the shopping cart. Gosh, I would love to learn all about that. I bet the paper by Rupert et al. would be a great place to start.

Color constancy - There has been all this research around the cool topic of how it is that our perception of the color of something doesn't change all that much when the illumination changes drastically. Like from the yellowish incandescent light in your living room to the blueish light outside. There is a huge difference in the spectra of the light hitting your eye, but we still see white paper as still being white. This is the kinda topic that makes people want to quit their day job and become a PhD candidate! But I'm not going to talk about it. Well... maybe I will mention it in passing.

Many roads diverged in this multicolored wood, and I am sorry that I could not travel them all. I took the one less traveled. 

Color memory

Here's what I am thinking: I have a picture in my head about what Starbucks green is. I see it as a darker shade of green that might be just a tiny bit toward the blue end. But, my memory of Starbucks periwinkle is wrong. If you don't believe me, just ask my wife. She is the world's authority on all my shortcomings, and would love to acquaint you with my multifarious imperfections. But, everyone's memory of the official Starbucks green is not quite perfect. How far off are we?

I just can't remember the name of this film

We all know that a banana is yellow, and a school bus is a slightly orange flavor of yellow, and the color of an orange is slightly weaker than true orange, but that carrots are true orange, which is why we call them carrots. These are all memory colors.

Carrots should really be called oranges

The idea of memory colors dates back to Ewald Hering in 1878. Loyal readers will remember that Hering has been mentioned in a few of my previous blog posts. Hering is the guy who developed the color opponent theory. This theory says that we can assess any color in terms of three attributes: where it fits between white and black, where it fits between red and green, and where it fits between yellow and blue. This is how color is encoded on its way to the brain, and this idea was baked into CIELAB.

Hering's three attributes of color

Hering made another contribution to color science. He said that our perception of the color of an object is effected by our memory of the color of a prototypical object. Like, if we see a banana that is kinda yellow, but not quite, we will remember it as being yellow. Remember how I said that I was gonna mention color constancy? Now is the time. Hering's theory has been used to explain color constancy. If the yellow of a banana has a slightly unusual shade, then our brain will use that fact to deduce the color of the illumination.

There is a prediction from Hering's theory of color memory that is important for the purpose of this blog. If his theory is true, then our memory will tend to bias toward the quintessential version of that color. We will remember our bananas being yellower than they really are.

David Katz reiterates Hering's theory:

... in the imagination we exaggerate colours of objects whose colours are generally distinguished only in terms of brightness, darkness or hue. If we ask a person to pick out a blue which will match the colour of the eyes of someone he knows very well, he generally selects a blue which is too saturated. If we ask a person to match a brick, he usually chooses a black which is too deep or  reds which are too highly saturated. Almost always he selects a colour which is too bright to match a bright object, one which is too dark to match a dark object, and one which is too saturated to match an object which is known to have a distinct hue.

Katz liked Hering's theory on the distortion of colors by our memory

If this theory is true, then our color memory is flawed, so our recollection of Starbuck's green is flawed. The practical message for everyone in the business of making sure that Starbucks has the correct shade of green is that the exact color of the logo doesn't really matter, since we will identify the logo by it's shape, and our brain will translate the color into the correct shade of green.

Wow. Big stuff here.

What does the research say?

Hering was a brilliant guy, and rates up there with Munsell as one of the Fathers of Color Science. But he was largely a theoretical guy. Have experimental results backed up his theories of memory colors?

An early investigation by Adams provided evidence that agreed with Hering, but it was inconclusive. 

From our investigations of the perceptions of the five natural objects grass, snow, coal, gold and blood, we may say that Hering and Katz were correct in claiming that the seeing of these objects is ordinarily affected by memory color. Although our investigation failed to give a quantitative measure of a single memory color, it was thus not unfruitful.

Adams (1923)

Five memory colors from Adams' paper

Not unfruitful? I didn't see a single fruit in their list of memory colors! It is likely that the hard results were lacking because of the lack of rigor in this paper. To be honest, the paper reads like a cheap and boring novel with pages and pages of one anecdote after another, and then a short experiment.

Bartleson provided a more rigorous test of memory colors, using colors of ten familiar objects: red brick, green grass, dry grass, blue sky, flesh, tanned flesh, broad-leafed summer foliage, evergreen trees, inland soil, beach sand. Here is their assessment:

Each memory color tended to be more characteristic of the dominant chromatic attribute of the object in question; grass was more green, bricks more red, etc. In most cases, saturation and lightness increased in memory. 

There is evidence of increased saturation in the memory colors. In most cases there are hue shifts with memory in the direction of what is probably the most impressive chromatic attribute of the object in question.

Bartleson (1960)

The grass is always greener in our memory

A bit more recently, Siple et al. did a similar test with six foods (carrot, corn, lettuce, lime, orange, and peanut), and agreed with the theme that we remember colors as being more vivid. Note that their test was the first that was literally fruitful, since they included oranges and limes.

Results indicated that, for hue and brightness, memory and preference were quite accurate for the objects tested; however, all subjects remembered and also preferred all items to be more highly saturated.
Siple and Springer, 1983

One could argue that trying to recall the color of grass is a bit problematic. After all, the color of grass varies with species. Is it Kentucky bluegrass? Fescue? Rye grass? Easter grass? The color also varies with the plenitude of rain, nutrients, and sun. And where my doggies have visited.

Three recent papers (one by Bloj et al., one by Pentz, and the final by Newhall et al.) sought to eliminate this problem of variability of the colors of real objects. Bloj asked subjects to bring along a familiar object. Even when recalling those familiar and well-defined colors from memory, the conclusion of this paper was that "Our results, on average, confirm that objects are remembered as more saturated than they are."

Somehow Johnnie graduated from Kindergarten despite his sub-par drawing skills

On to Pentz's paper. He taught a color class for several years, and recruited the members of each class for an experiment, eventually testing 283 people. The people in the class were shown a blue piece of plastic and were told that they would need to recollect the color later on. They each had a chance to hold the plaque and could look at it as long as they wanted. Later, they were shown a collection of 24 plaques which included the one they had looked at. "Only thirty percent of participants at plastics coloring seminars were able to correctly identify a color observed only an hour earlier." While the correct plaque was determined by the most participants, the two next most likely guesses had a color difference of about 10 ΔE from the correct plaque.

(How big is 10 ΔE, you may ask? Imagine a color match that is as big as you might consider acceptable for production. Then multiply that by 2 or 3.)

Newhall et al. looked at our short term memory of colors in order to eliminate the ambiguity for familiar objects. The subject was shown a color for 5 seconds, given a 5 second break, and then asked to adjust knobs to recreate that color. Here is one of the conclusions from the paper:

Significantly more purity and somewhat more luminance were required to complete the color matches by memory than were necessary for the simultaneous matches. This principal result was confirmed by the results of three supplementary experiments.
Newhall, Burnham, and Clark (1957)

Newhall et al. found that we remember colors as being higher in chroma (by 1.7 steps in Munsell chroma) and somewhat lighter. They also found no consistent change in hue between what we remember and what we see.

The typical migration pattern of a color trapped in a brain

How big is a step in chroma of 1.7? The data is all in the paper. I could type it all into a spreadsheet, convert it into CIELAB, and then compute color differences. But I could just be lazy and wave my hands. Fully saturated colors go up to maybe 15 in Munsell chroma, and maybe 100 in CIELAB C*. A step of 1.7 in chroma is roughly 10 ΔE. I dunno. I think this is kinda big for a 5 second delay.

One common theme from these experiments is that colors are remembered more vividly than they actually are. Whether or not colors are lighter in our memory and whether there is a systematic error in the hue are both up for debate.

Colligation

The ancient Greek, Ptolemy, developed a set of equations that could be used to predict the positions of the planets at any time. The equations were based on a lot of wrong assumptions, like "the Earth is in the center, and all the rest of the celestial bodies move in circles that revolve around other circles". The model worked, at least to an extent.

A millennium or so later, Copernicus decided that the Sun belonged at the center. Then Kepler came along and decided that ellipses made the whole thing simpler than the circles in circles thing, and then Newton provided the big colligation. The inverse square law of gravity was the grand unifying theory that explained the whole enchilada. If the pull of gravity goes in inverse proportion to the square of the distance between the objects, then planets will travel in Kepler's ellipses. Eureka!

By the way, colligation means "to subsume (isolated facts) under a general concept". I really love that word. It explains the essence of what I think it is to do Science: to find simple theories that explain lots of data.

We are ready for a colligation of our understanding of color memory. We have all this data from these studies. We have a generalization of how saturation changes when it gets implanted into our memory. It's a bit fuzzy what happens with hue and lightness, since the data doesn't always agree. We need an explanation that can tie it all together and explain some of the anomalies.

In this case, the colligation was fairly recent, by Bae et al. in 2015. The idea is pretty simple. We have a limited number of folders in the filing cabinet in our head. Although we can distinguish perhaps millions of colors, there are eleven basic folders where we store colors, at least in the English speaking world. The folders are labeled white, black, gray, red, orange, yellow, green, blue, pink, brown, and purple. This was the result from Berlin and Kay, and also in the groundbreaking experiment that I never got around to publishing.

How many colors are in your rainbow?

Here is the grand and glorious theory of color memory distortion.....

When we want to store the color of an object in our brain, the first step is to categorize it into one of perhaps eleven archetypal colors. From there, presumably, we may make modifications to distinguish from the archetypal color (yellowish green, or dark red), and the modifications get stored along with the general category. Later when we retrieve that color from our memory, the archetypal color gets weighted a bit more than the modifier.

Evidence from Bae

Bae et al. had the participants try to remember 180 colors, equally spaced in hue, all with L* = 70 (fairly light) and C* = 38 (somewhat saturated). They saw the color for 100 msec, the color was removed for 900 ms, and then they had a chance to select the color from a ring.

The results of the paper are summarized in my drawing below. There are seven regions. Within any of the regions, for example, the blue one, people will tend to distort the hue toward the solid line which represents the archetypal example of that hue. (Four of the eleven basic colors were left out. White, black, and gray don't have a place on the hue circle. And since their L* was fairly high, they missed out on brown. They almost missed red.)

Hieroglyph found in a Mayan tomb, hitherto-for undecipherable 

This explains why the hue of a color sometimes shifted in the experiments, and sometimes not. But the color memory experiments seem to all agree on one thing. Our memory of a color is generally more saturated than the actual color. How does the eleven-folder theory of color memory explain this?

Here is a quote from Heider that can explain this:

It was quite clear, without further analysis, that the most saturated colors were the best examples of basic color names both for English speakers and for speakers of the other 10 languages represented.

When we think red, we don't think some wimpy-butt red. We think fire-engine-lipstick-Corvette-candy-apple-OMG-I'm-bleeding red. It only makes sense that most of the colors that were tested in the experiments cited above would not be the most saturated colors imaginable. Hence, our memory would tend to distort most of the colors in the experiments toward the extreme of saturation.

There are some archetypal colors that don't fit Heider's hypothesis, namely brown, gray, and pink. I would take a wild guess that these are the exceptions to the rule in the previously described experiments.

Why eleven?

Bae's research suggests that the eleven basic color names are the appropriate number. Or rather, it does not suggest that there are colors beyond the seven which qualify to be archetypal colors. But Bae's experiment, awesome as it was, only looked at 180 colors - all of which had the same L* and C*. There is quite a bit of uncharted color space.

Based on my personal experience, I would like to think that I have more than just eleven archetypal colors. I mean, I see tan, coral, olive green, and plum as distinct colors in their own right.

My candidates for induction into the Hall of Archetypal Colors

In some languages, such as Russian, Japanese, and Italian, there is a separate word for light blue which stands on it's own as a distinct color. So, maybe there are twelve archetypal colors? Dimitris Mylonas (Mylonas and MacDonald, 2015) suggested that lilac and turquoise also belong on the list. In two other papers, he has named a much larger collection, including cream, lime, olive, salmon, mustard, peach, tan, and coral.

So, I don't think we can say at this time that there are exactly eleven colors that serve as archetypal colors in our memory. There could be more. It also seems quite plausible (to me) that the number is different for different people. I would think that people who deal with colors all the time (like artists, graphic designers, fashion designers, interior decorators, and the spouses of color scientists) might have developed a wider collection of focal point colors. On the other hand, it could be that the relatively small collection of focal point colors are a result of something hardwired in the brain.

Here's another interesting thought. We know that some people have perfect pitch, an uncanny knack to identify musical notes. All of these studies looked at people's color memory in the aggregate. Perhaps there were a few individuals whose superpower is to have perfect hue? I have heard more than one person make that claim. Of course, one person who made that claim also told me that he was raised from infancy by a troop of iguanas in a volcanic crater. He probably learned it from them.

All interesting stuff for further research!

Non-References

Burnham, Robert W., and Joyce Clark, A Color Memory Test, Journal of the Optical Society of America, Vol 44, No 8, Aug 1954

Rupert, Andrew Hurley, Rachel Randall, Liam O'Hara, Charles Tonkin, Julie C. Rice, Color harmonies in packaging, Color Research & Application, Volume 42, Issue 1, 28 March 2016

Yu, Luwen, Stephen Westland, Zhenhong Li, Qianqian Pan, Meong Jin Shin, Seahwa Won, The role of individual colour preferences in consumer purchase decisions, Color Research & Application, Volume 43, Issue 2, 10 October 2017

References

Adams, Grace Kinckle, An Experimental Study of Memory Color and Related Phenomena, The American Journal of Psychology, Vol. 34, No. 3 (Jul., 1923), pp. 359-407

Bae, Gi-Yuel, Maria Olkkonen, Sarah R. Allred, and Jonathan I. Flombaum, Why Some Colors Appear More Memorable Than Others: A Model Combining Categories and Particulars in Color Working Memory, Journal of Experimental Psychology: General, 2015, Vol. 144, No. 4, 744–763

Bartleson, C. J., Memory Colors of Familiar Objects, Journal of the Optical Society of America, Vol 50, No 1, Jan 1960

Berlin, B., and P. Kay, Basic color terms: their universality and evolution (Stanford, Calif.: Center for the Study of Language and Information 1969).

Katz, David, The World of Colour, Kegan, Paul, Trench, Tubner, 1935, p. 164

Heider, Eleanor Rosch, Universals in color naming and memory, Journal of Experimental Psychology, 1972, Vol. 93, No. 1, 10-20

Hering, Ewald, Outlines of a theory of light sense, Grundzüge der Lehre vom Lichtsinn 1905, translated 1964, Harvard University Press

Mylonas, Dimitris and Lindsay MacDonald, Online Colour Naming Experiment Using Munsell Samples, European Conference on Colour in Graphics, Imaging, and Vision - CGIV, June 2010

Mylonas, Dimitris, Mathew Pruver, Mehrnoosh Sadrzadeh, Lindsay MacDonald, and Lewis Griffin, The Use of English Colour Terms in Big Data, May 2015, AIC Midterm 2015

Mylonas, Dimitris and Lindsay MacDonald, Augmenting Basic Colour Terms in English, Color Research and Application, Volume41, Issue 1, February 2016

Newhall, S, M., R. W. Burnham, and Joyce R. Clark, Comparison of Successive with Simultaneous Color Matching, JOSA 47, No. 1, Jan 1957

Pentz, Anthony J., Does color memory exist?, SPE/ANTEC 1999 Proceedings (Society of Plastics Engineers Annual Technical Conference and Exhibit)

Siple, Patricia, and Robert Springer, Memory and preference for the colors of objects, Perception & Psychophysics, 1983,34 (4), 363-370

Looking for case studies!

June 26, 2018, 6:00 am

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Proof of concept has been established on my ColourSPC project. Over 561K color measurements have been compiled of roughly 3,000 production colors from nine different sources, including data from packaging, newspaper, toner-based, and offset printing, as well as photography, and plastics. The analysis demonstrated that when a color process is in control, the new Zc statistic will follow a specific known distribution.

I am moving to the proof of utility phase, where I hope to show that my new techniques can turn color data into information that is useful for color manufacturers.

I am looking for case studies; people with color manufacturing data and a burning question that they would like answered with that data. Contact me if you want to be part of this exciting new research! john@johnthemathguy.com

Example questions

Some examples of questions that can be answered with ColourSPC:

    Is this data point an outlier, or just somewhat unusual?

    Was this production run under control?

    What is the major contributor to color variation?

    Did this new piece of equipment or software, or a change in process reduce color variation?

    Can this process reliably meet the color tolerance that my customer wants?

References

Statistical process control of color, approaching a method that works, Sept 12, 2017

Statistics of multi-dimensional data, theory, Nov 14, 2018

Statistics of multi-dimensional data, example, Nov 21, 2017

Statistical process control of color, a method that works, Jan 16, 2018

Is my color process going awry?, Feb 14, 2018

Is my color process all wonky?, Feb 28, 2018

Statistical process control of color, TAGA, March 2018

Applications of ColorSPC, Print Properties Council, March 2018

State of the art in Extended Gamut printing

August 21, 2018, 8:54 am

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I had a series of blog posts on expanded gamut (parts one, two, and three) which were very popular. When I say "very popular," I of course mean that I have indirect evidence that there may have been one person -- possibly in Spokane, WA -- who stayed on the web page for longer than one minute. While it is likely that he or she was not actually looking at the screen at the time, we cannot dismiss the possibility that someone actually read part of one of the previous blog posts.

Obviously, I need to follow up, to provide some practical advice on expanded gamut. Since I am only capable of impractical advice, I have called on a friend who has convinced me that he knows stuff about this stuff. I turn this over to today's guest blogger, Mike Strickler.

Introduction

John has treated us to an entertaining history of attempts to achieve more colorful results by overcoming the limitations of 4-color printing. But what of the situation today? What does “Extended Gamut” mean in the present context; what do these solutions look like? EG systems now range from simple arrangements consisting of nothing more than Photoshop and a multichannel output profile to entire integrated workflows with proofing and elaborate options for spot color handling. But for all the recent attention paid to the subject, there is still a lack of industry consensus on just what a constitutes a proper EG separation, and any effort to make sense of the subject typically faces a mixture of conflicting proprietary claims, incomplete studies, and persistent misconceptions. It is still the Wild West. Perhaps by considering how these systems came to exist we might better understand what they actually do and how well they fulfill their purpose.

Extended-gamut today: a dual heritage

We can simplify the origins of all EG systems to two distinct lineages, each corresponding to a different need: Systems that convert images and those that convert spot colors. Combining and reconciling these two functions is the key challenge faced by designers of EG systems today.

Spot color conversion systems: a tyranny of rules

As we read earlier, several decades ago some clever individuals saw that one might reproduce a wide range of spot colors as equivalent process builds using CMYK with the addition of secondary inks such as a red, orange, green, blue, or violet. This was in the days before digital color management, so lookup tables were laboriously built from trial press runs and served as guides for converting colors, object by object. These systems mostly used AM screening, so immediately the question of screen angles had to be addressed. The usual scheme of 0, 15, 45, and 75 degrees was seen as imperfect because it forced a choice of either creating additional intermediate screen angles, increasing the risk of moiré, or sharing screening angles among complimentary colors such as cyan and red/orange and magenta and green, an unpopular choice as it raised the risk of color shifts caused by misregistration on press—a reasonable concern when printing vector objects, with their well-defined boundaries. A near-consensus converged around two simple rules for multicolor separations:

1. No color shall be converted to more than 4 process colors. Three is even better.

2. Complimentary overprints, such as cyan-red/orange and magenta-green, must be prevented. Who needs them, anyway?

These rules continue to be applied in a majority of EG systems, even those updated with automatic color-managed conversions. Spot color tints and overprints are handled by arithmetic interpolation or other simple means. The intricacies, and limitations, of these schemes will be discussed in the next blog. For the remainder of this one, we’ll focus on image conversions.

Images conversion systems: the rise of multichannel ICC profiles

While those brave pioneers were building their lookup tables, deft prepress workers were enhancing CMYK images with “touch” or “bump” plates of stronger colors. This practice can be seen as the true progenitor of multichannel extended-gamut systems.

With rare exceptions, modern image conversion methods rely on ICC color management. For generating multicolor (CMYK+N) press separations a basic system includes two profiles, one for the source color apace (often RGB) and one for the multicolor destination space, a CMM (Color Matching Method), AKA a “color engine,” and an application such as a RIP, color server, or other color-managed program such as Photoshop to interpret the source pixels and build the new image.

The profiles contain lookup tables that translate color appearance values (XYZ or Lab, AKA the PCS, or Profile Connection Space) to device values and vice versa. The CMM draws smooth curves through the LUT points and interpolates all intermediate values. PCS to device (or B2A) tables may contain a good deal of “secret sauce” for enhancing printability, saving ink, increasing the amount of black in neutrals, etc.; separate tables are built for different rendering intents or gamut mapping strategies. On top of this, device-link profiles may be employed to bypass the PCS conversion and apply even more rules, e.g., to exempt certain colors from the conversion. The key points to know about multicolor ICC systems are:

They are automatic, fast, and precise.

They are able to juggle multiple objectives, the two most important being accuracy and smoothness of output color, even up to 7 or more output channels.

Any combination of output channels may be used to fulfill objectives.

 Results are conditioned by the quality and completeness of underlying measurement data.

Two systems, two outcomes

Image conversion is still an important function of EG, and systems do perform differently depending on their underlying logic. To illustrate this we can look at the results from converting an RGB test image with two very different solutions, one developed primarily for simulation of spot colors—you might say an heir to those clever lookup tables—and the other a typical representative of ICC color-management, the current default method for converting images. The test image contains a smorgasbord of truly devilish color conversion challenges: delicate flesh tones, textures and smooth gradations in deep, saturated colors, and full-tone black and white images. Any serious defect in a color conversion system is unlikely to escape detection here.

Details: Some gamut compression will be required convert these images to these smaller multicolor output spaces: In the first example perceptual rendering intent was used; in the second, relative colorimetric with black point compensation was chosen as the best available option with that system. Black generation (GCR) was adjusted to be as similar as possible in both cases.

System A. This is a conventional ICC-based system, available as a standalone profiling application (to be used in ICC-compliant workflows) and optional color server, which was employed here for the conversion. The underlying measurement data of the profile (for coated packaging board) is plotted in Lab space below. It shows a good balance of shadow, mid-tone, and highlight samples. A modest number of complementary color pairs (C-O, M-G) and extra-color overprints (O-G, V-G, OV, OVG) are present.

The results, shown below, are good. Details and tonal separations are preserved in the deepest and most saturated colors; gray balance is excellent, and no contouring, banding, or posterization is evident. Gradations are smooth.

The OGV separation view below shows a long scale for the OGV channels; they extend deep into colors that are printable with CMYK alone (flesh tones, underside of sunflower).

The graph below, derived from the lower-right image of the jack-o-lantern plant, shows how a range of colors from red-orange to dull green is composed. The extensive interleaving of channels, including small amounts of complementary colors, is a very probable contributor to the visual smoothness of the color transitions.

This system would be a good choice for demanding image reproduction work.

System B. Here we have a non-ICC system sold as an option for a popular workflow suite. It is a bit of a hybrid, its profiling scheme showing echoes of earlier simple spot-color lookup systems: Complimentary colors (C-O, M-G), extra colors (O.G.V) do not overprint, and no build exceeds 4 total colors. Otherwise, its profiles contain an abundance of tint and overprint data, as seen in this Lab plot:

The profile structure is unique, consisting of 4 4-color charts, thus simplifying its design. As we’ll see, simpler is not necessarily better, as when approaching multidimensional problems like image transforms in 7-color space.

The converted test image below predictably shows some differences with Sample A. Color transitions are more abrupt, as shown clearly in the patch chart at the top of the form.

The OGV separation view shows very limited replacement of in-gamut CMY by OGV inks, though this reportedly may be adjusted to some degree in the software. Gradations in these channels are noticeably less differentiated than in System A. The overall appearance of the n-channel separations is more like that of old-fashioned touch colors than fully functioning process channels. The red-green transition contains much less channel interleaving than in Sample A.

Two image comparisons will suffice to show some implications for these different separation schemes. In the lower area of the still life image below we see the dramatic impact of the compacted tonal scale of the violet channel in System B (right). Deep blues are hollowed out and posterized. Faithful rendering of dark, saturated colors is a critical attribute of any good color reproduction system, and this example is decidedly sub-par. System A (left) shows normal results.

The next image detail is a good test for reproduction of subtle color transitions. As seen in the System A image (left), the jack-o-lantern displays a nicely nuanced transition from orange to yellow-green in which a multitude of slightly varying flecks of yellow-green and yellow-orange can be seen. The System B image (right) looks comparatively crude, with a relatively flat, featureless orange abruptly breaking to an undifferentiated yellow-green. (This may be difficult to see in this low-resolution image.) Such defects are not correctable through image retouching, as the separations simply lack the necessary supporting tonal information.

This image also shows an interesting feature of System A. In the transitional color regions we see the presence of the complementary orange-cyan combination:

 These colors, as well as green and magenta, are of course mutually cancelling and therefore commonly regarded as unnecessary in a press separation, a belief so widely accepted that it might be regarded as one of the tenets of extended-gamut printing. As noted earlier, such combinations are excluded from the separation in System B. However, closer study reveals a useful role for these “interstitial” colors in smoothing transitions.

A cautionary note on profile accuracy

An otherwise capable multicolor system may be compromised by the sort of measurement data underlying the profile being used. Here is a Lab plot of a typical 7-color measurement set used by a popular ICC profiling application.

Notice the extreme abundance of dark overprints, far in excess of any possible utility, and the skeletal representation of mid-tones and highlights. This gaping void must be interpolated, literally guessed at by the CMM. The resulting converted images are smooth, but intermediate values are largely fictitious. The less linear the device output is the worse the fiction! There is no known workaround with this application.

Conclusions

Modern multicolor extended-gamut systems must capably convert a variety of elements, including images, vector objects, and spot and process colors, singly and in combination. Systems based on older spot-color matching schemes may have a tougher time converting images compared with systems based on ICC multichannel profiling. Nonetheless, these older systems continue to enjoy popularity in package printing, where the dominance of vector designs gives rise to concerns about printability that may compete with the need for high image fidelity. In the next blog we’ll see how these two schools of thought play out in actual practice, with particular focus on strategies and techniques for converting spot colors. If space allows we’ll also touch upon the arcane subject of EG proofing.

Are you having a multicolor crisis of your own? Are battles over your system configuration leaving you black and blue? Please feel free to post comments and questions here, or send them to mike@mspgraphics.com.

About today's blogger

Mike Strickler is the guy I call on the rare occasions when I want to sully my mind with practical concerns about color management. Mike is a specialist in graphics arts and color management. He is an Idealliance G7 Expert, CMP Color Management Master Trainer and member of PIA and IAPHC. Based in the San Francisco Bay and Los Angeles areas. Specialties: Color management, printing, remote proofing, and photography.

Mike is the principal at MSP Graphic Services.

A dialog on the superiority of humans over canines

August 25, 2018, 8:14 am

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Which way is north in Munsell color space?

January 23, 2019, 5:33 pm

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I wrote a blog post for Inkjet Insight about the Munsell color space. I don't want to spoil it for anyone, but the post is mostly just a gateway post to one about the CIELAB color space. For the Inkjet Insight post, I had my crayons pose for the aesthetically pleasing picture below. I do expect an Emmy for the picture, but I will try to appear surprised when I get called to the stage.

Happy crayons get together for a crayon picnic

Boy! Did that picture stir up a hornet's nest when I posted a link on LinkedIn! Two of my color scientist friends took umbrage. You may be wondering about my choice of the word "friends". Perhaps I use the term loosely, but Danny and Dave are the closest thing I have to friends, I mean, aside from Truffle and Mozart. And I feed Truffle and Mozart twice a day.

Here's Danny's malicious comment: "It seems that you have ordered the crayons as CIELAB would but not as Munsell does."

Dave's equally viscous comment: "Oops. Danny is right of course.  Unless, ... this is a view from below! To be more CIELABish I actually reverse the hue direction in my hanging Munsell Tree."

The gauntlet has been thrown down!!

I gotta ask you gentlemen, Danny and Dave, which Munsell color system you are referring to?

First, there is nothing inherently in the Munsell notation (7.5PB 4/6) that tells us which color points east (0 degrees) and whether orange is clockwise or counterclockwise of red. The Munsell notation for each color includes one of ten designators (R, YR, Y, GY, G, BG, B, PB, P, or RP) to specify a hue family. Within each hue family, there are ten steps which (oddly enough) are numbered from 1 to 10. Each number is one-step change in hue. Thus, 7.5PB is a unique specification for a hue, without any implied orientation.

Take that, Danny and Dave!

Second, there is a disagreement between Albert Munsell and Albert Munsell about the direction of red. As shown in the image below, his 1913 atlas has red pointing at around 45 degrees clockwise of east.

Page ripped from the Munsell Color Atlas of 1913

But in Munsell's New York Times 1919 bestseller "A Color Notation System" the master shows red pointed due north.

More vandalism, but to Musell's A Color Notation System

Both of these Munsell illustrations show orange as being counterclockwise from red. Pretty much the same as the way my Crayolas arranged themselves, and also, the way that CIELAB is arranged. Since there is no "correct" direction for red to point, I feel justified in pointing red to the east.

How do you like the color of them apples, my Dynamic D-named Duo!?!??  Well, I'm not done yet!

Third, the ASTM disagrees with both of these Munsell orientations. In 1968, the ATSM provided us with a "standard method of specifying a color by the Munsell system" (ASTM D 1535). Note that in the ASTM system, red points to the north. This agrees with the second illustration, but hang on a sec while I expound on some ASTM D 1535 trivia that is likely to come up the next time Danny, Dave and I get together for sushi.

ASTM D 1535 dictates this orientation

ASTM D 1535 also assigned a number for each discrete step of Munsell hue angle, from 1 to 100. Interesting point -- their notion of hue "angle" is in centicircs. I just made that word up. One centicirc is 3.6 degrees. It's about time we went metric and got past this silly Babylonian notion that we should measure arcs by comparing against the size of arc that the Earth makes around the Sun in a day. Approximately a day.

The ASTM adopted the obvious convention that 0 Munsellian centicircs would be at 18 degrees counterclockwise from north. I mean... of course. Well... I need to clarify. No one ever really told me whether "true" red was 0R or 5R. I guess I assumed it was 0R.

Also D 1535 is not explicit, but I think that 0 centicrics is not allowed. That has to be called 100. Kinda like the zero-phobia that says that midnight is 12:00 instead of 0:00. And that the first day of a month is 1, rather than 0.

More importantly, note that contrary to "normal" analytical algebra, Munsellian centicircs increment in the clockwise direction! I'm going to report them to their calculus professor!

But hang on. Here's the big thing. Even more importantly, and contrary to Munsell's two books, in the D 1535 system, orange is clockwise from red. O.M.G.!!

Dave boastfully mentioned his "hanging Munsell Tree". Not to be outdone, I provide a picture of my own hanging Munsell Tree. In my case, the world famous Munsell Color Model is joined by the world famous Munsell Color Model Model, Madelaine. We can see that my tree and Dave's tree both adhere to the "orange is counterclockwise from red" convention.

Wild times at the John the Math Guy household

Since there seems to be some latitude in the orientation of the color wheel in Munsell space, I claim that I am well within my rights to orient Munsell space in such a way as to serve as a stepping stone to CIELAB.

For those of you who are wondering about the significance of all this detailed historical research, let me be clear. It's all about me proving that I am right. Nothing else really matters.

The Color Name Conundrum

January 30, 2019, 7:12 pm

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ISCC/AIC Munsell Conference, 2018, Keynote by John Seymour

It’s a common argument that my wife and I have. We are at a store or movie or coffee place, and I will comment on another woman’s blouse. “Hey, Honey. Look at the woman in the turquoise top. Isn’t she cute? … She smiled at me… And she handed me a card with her number on it.” Madelaine will invariably respond with “That’s not turquoise!” She may say that it’s teal, or aqua, or beryl, but she will never agree on the color name that I chose. I can blather on all I want about how I am a world-famous color scientist who was asked to give a keynote for the Munsell Conference. It won’t matter. What do I know about color?

The lady in the allegedly turquoise top

This time, I decided that I would win the argument. I started with Merriam-Webster’s dictionary since it is an authoritative reference that would show I was using the color name correctly. This dictionary defines turquoise as “a bluish-green color”, and follows up with the full and much more explanatory definition “a light greenish blue”.

I exercised due diligence and spoke directly with the person who wrote the full definition, Kory Stamper, to help resolve the argument with my wife. She politely (and wisely) declined to get involved. But I could tell that she was agreeing with me.

[As an aside, the exciting thing about attending ISCC/AIC Munsell conferences is that eminent chromo-lexicographers like Kory might be in the audience when they are called out in a keynote address.]

Dictionary.com defines turquoise similarly: “a greenish blue or bluish green color”. The Oxford English Dictionary provides a similar definition but leans more to the greenish side: “a greenish-blue color”. So, it seems we have a consensus between the dictionaries. But more importantly, we have a consensus in which I win the argument!
The image below shows blue, greenish-blue, bluish-green, and green. The blouse is definitely close to bluish-green, so turquoise is indeed an appropriate descriptor of the blouse color. Did I mention that I claim victory?

The happy shades between blue and green

But I decided to check one last dictionary, Webster’s Third New International. The definition in this dictionary is at once beautiful and tedious.

1) a variable color averaging a light greenish blue that is deeper and slightly greener than average turquoise blue, and greener and deeper than average aqua or average robin’s-egg blue (sense 1)

My stalwart research assistant suggests that the definition might be a bit too complicated

You can see that our puppy, Mozart, was puzzled when he read it, so I diagrammed the definition out for him (see next image). He thanked me when he saw the diagram, and went off to bark a friendly greeting to a squirrel that was outside. By the way, Mozart is not named for Hank “the Tank” Mozart. You will recall that Tank played defensive hatchback for the Green Bay Bruins. His claim to fame is that he scored the winning basket over Jack Nicklaus in the 1968 War of the Roses Tournament. Madelaine and I named the dog after the less-well-known Wolfgang “Wolfie” Mozart.

An Applied Math Guy reads the dictionary

In most dictionary definitions, the lexicographer works to define complex words in terms of more basic words. The Webster’s Third definition of turquoise is unique in that it defines the color relative to other colors which are just as non-basic as turquoise. To really make sense of this tortuous definition of turquoise, I realized that I had to generate similar diagrams for aqua and robin’s egg blue and turquoise blue and greenish-blue, and then for each of the other colors that were called out in those definitions. It only took me three days to generate the following table that delineates the territory of the ten tones in the turquoise tautology. It is clear from this that color names are very precisely defined.

A handy reference for color names in the blue-green family

But I still wasn’t happy. The intertwined definitions haunted me. Where Kory is the Steinbeck of chromo-lexicography, whoever wrote the lovely and sadistic color definitions from Webster’s Third was the Faulkner. I simply had to find out who this anonymous author was.

Luckily, it didn’t take long. The list in the front of the dictionary of contributing experts provided me with the answer. It had to be Isaac Godlove.

[As an aside, the exciting thing about attending ISCC/AIC Munsell conferences is that the audience will recognize the names of prominent researchers in color when their names are mentioned in a keynote address. Let me tell you, the cheers were deafening! Everyone recognized that Godlove was the third author of the seminal paper “Neutral Value Scales. I. Munsell Neutral Value Scale” from the Journal of the Optical Society of America in 1933.]

Of course, some of the people cheering also recognized that Godlove was the director of the Munsell Research Laboratory from 1926 to 1930. What an enormous coincidence that he should get mentioned in the keynote at the Munsell Conference! A few chromo-historians in the crowd actually knew that Isaac Godlove was the chair of the ISCC Committee on Measurement and Specification in 1933. (Note again the coincidence that the ISCC was one of the organizers of the Munsell Conference!)

While Godlove was chair, a group of pharmacists approached Godlove about the need for a definitive guide to color names. This eventually led to the National Bureau of Standards runaway best seller “Color – Universal Language and Dictionary of Color Names”, which became a Broadway play of much acclaim. This absolutely delightful standard carved the Munsell Color Space into 267 regions (called Centroid Colors) and gave each region an intuitive designator like “bG 159”, along with a euphonious name like brilliant bluish green.

A hue slice from the NBS standard on color names

As if that wasn’t enough to earn a prominent spot in my bookcase, the authors dug through all the available color naming guides (like Maerz and Paul, Plochere, and Ridgway) to determine the Munsell coordinates for each of the color words that were defined. As a result, the NBS standard further provides two lists: 1) a list that goes from common color name to the appropriate Centroid Colors in Munsell space, and 2) a list that provides all the color names that have been associated with each of the 267 Centroid Colors.

I was ecstatic. I quickly saw that this book provided a solution to the recurring argument that I had with my wife. The solution is astoundingly simple. Whenever I am within earshot of Madelaine, I just have to go through four simple steps before I utter any color names.

Step 1: Measure the color in question. For example, I called up the woman in the turquoise top, explained the situation, and met her at Starbucks with my spectrophotometer so I could measure her shirt. She understood my predicament perfectly, and agreed to share a Starbucks with me. Her shirt measured CIELAB of 86, -47, -4. Her name is Teal, by the way.

Yes, it’s a bit of a bother for me to carry a colorimeter with me at all times, but what color scientist worth his or her salt doesn’t carry one for the occasional color measurement emergency?

Step 2: Convert from CIELAB coordinates to Munsell designation. One could make use of the Munsell Renotation Data. The official version is conveniently available on the RIT website to do the approximate conversion, but several people have written software that does this. Harold Van Aken (of Wallkill Color) provided a piece of software as a freebie in honor of the Munsell Color Conference. (Yet another astounding coincidence.) Paul Centore has graciously provided an open source conversion, and Danny Pasquale sells an inexpensive tool called PatchTool that provides this function among others. The CIELAB coordinates of Teal’s allegedly turquoise shirt were thus converted to 5BG 8.5/9 in Munsell notation.

[As an aside, the exciting thing about attending ISCC/AIC conferences is that two of the three people who wrote software for this conversion (Paul and Danny) were actually in the audience for the keynote.]

Step 3: Convert from Munsell designation to Centroid colors. It goes without saying that it is pretty quick and easy to leaf through the diagrams (like the one below) in the NBS standard to find the Centroid corresponding to any Munsell designation. In this case, the Centroid Color is 159. Yes, it’s a bit of a bother to carry the NBS standard with me, but it’s a small price to pay for me to prove that I am right in an argument with my wife.

Step 4: Look up the color names listed under the Color Centroid. In the case of Centroid 159, the list is rather short. It includes Beryl Green, Bewitch, Blue Green, Bluish Green, Bright Aqua, Bright Aqua Green, Bright Emerald Green, Bright Green, Bright Jade Green, Bright Turquoise, Bright Turquoise Green, Chill, Crest, Du Barry Blue, Festival, Green, Ice Boat, Light Emerald Green, Lilting Green, Naid, Persian Green, Picturesque, Pool Green, Promised Land, Salome Blue, Song of Norway, Sprite, Sulfate Green, Turquoise Green, Venetus, Venice Green, … and of course, Turquoise. I win!

The fact that this particular color has 32 valid names shows that our assignment of color names to physical colors is not nearly as precise as Godlove and Webster’s Third would have us believe. We need a system like Munsell or CIELAB (or NCS or RAL or Pantone) in order to accurately communicate colors. That’s an important thing to realize, but the more important takeaway from the research presented here is that I won the argument!

May you enjoy arguing with your significant other as much as I do.

International Day of Women and Girls in Science

February 11, 2019, 8:41 am

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Today is, of course, the International Day of Women and Girls in Science. I should clarify, As I write this post, it is the International Day of Women and Girls in Science. As you read this post, it may no longer be the International Day of Women and Girls in Science. This is sad, because the International Day of Women and Girls in Science should go on forever, to remind us that Science (with a capital S) is not just about guys, but it's about guys and gals. I personally would like for Science to not be just a men's club.

If you are a blog post aficionado, and you are spending your International Day of Women and Girls in Science reading blog posts about the International Day of Women and Girls in Science, I'm gonna guess that you are getting tired of reading about Marie Curie. I mean every blogger and his/her left-handed third cousin twice removed from Akron is writing today about Marie Curie. I certainly don't want to belittle her contributions to Science. I mean, there's that whole Nobel Prize thing. I guess that's kind of a big deal.

But I do want to highlight someone else, someone who has not gotten the recognition that she deserves.

My first thought was Ada Lovelace, who was the very first computer programmer. She programmed a computer developed by Charles Babbage, the Analytical Engine. She programmed the computer before it even existed. How cool is that? I'm not sure how she debugged her code.

A model of Babbage's Analytical Engine which has been on backorder since 1837 

Naaaahhhh... she's been overdone. They even named a programming language after her. Not "Lovelace". That has to do with a film that no one will admit to having watched. The language was Ada.

Then there's the early programmers of the ENIAC -- a computer which actually existed. Likely becasue of the war, these Rosie the Riveters shown below were the first to program the ENIAC. The programming on this beast wasn't done by typing in stuff like "If x = b, then ...". It wasn't even done by flipping switches for 0s and 1s. It was done with short cables that connected various arithmetic units together.

Kay McNulty, Betty Jennings, Betty Snyder, Marlyn Wescoff, Fran Bilas and Ruth Lichterman were the original programmers of the ENIAC

My next thought was Florence Nightingale. She deserves some credit, since she doesn't get the credit that she deserves. I think most people would remember her as a caring nurse at a field hospital during the Crimean War (in Turkey, circa 1856). This is true. She was a nurse to the soldiers. But to call her "just a nurse" significantly underplays her contribution to Science.

As a nurse, she saw many soldiers die, and was understandably concerned. But rather than just being compassionate, or complaining about the constant deaths of the wounded, she did something about it. She took data. She drew some cools info-graphics. I have no idea what the chart below shows, but someone told me that it is a visualization of the mortality data by month.

Early infographic on field hospital mortality

In the end, Nightingale determined that unsanitary conditions were a major deciding factor into whether a wounded soldier survived. I see this as a three-fold win. First, of course, there was the immediate short-term benefit of saving lives. And that's what war is all about, isn't it?

The second benefit is one that is clear even today when someone goes into surgery. The area of the incision on the patient is carefully cleaned. The surgeon washes his or her hands very thoroughly, and is careful not to get the hands dirty after that. Even in every hospital room, we see a hand sanitizer dispenser on the wall.

The third benefit is more nebulous. From the fact that Nightingale is remembered as a nurse, I conclude that this point may have been lost on the general public. The nebulous and under-appreciated learning from this story is that data can drive decision making. She took data, she analyzed data, came to conclusions based on that data, and those conclusions led to significant improvement to the process.

To quote William Deming, an early proponent of statistical process control, "In God we trust. All others bring data."

Then I come to the woman who I decided would be the topic of this blog post, Dorothy Nickerson. She started her work at the Munsell Corporation and went on to work the bulk of her career at the US Department of Agriculture. She was instrumental in the development of measurement of color, process control in the manufacturing of color, and development of international standards for color.

This looks like a good paper!

I wish I had started this post a few days ago, cuz I would have done a bunch of research on her and presented a really cool and compelling story. My apologies. I promise to get to that blog post some time in the future.

I'm forever blowing bubbles

March 25, 2019, 3:20 pm

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Bubbles. What's not to love? There just have to be some patents on making the fun little things.

The bubble mitt

A patent came to my attention today -- one where I can't help but say, "Gee whiz, I wish I'd thought of that!" The title of the patent: "Wearable article and packaging for generating bubbles". I'll wait for everyone to return from an Amazon search before continuing.

The image below shows the miraculous and ingenious invention. On the right, we see the result when "two thin films of plastic are welded together to form an article that, in one embodiment, is sealed around most sides but open at a proximal end to form a pocket to allow entry of a body part such as a hand." Note that the inventors cleverly left open the possibility that the body part could be something other than a hand. I am positively delirious considering the body parts that I might generate bubbles with!

In a patent, it is generally a good idea to give a broad description ("a body part") and follow that up with one or more specific embodiments to cover what you intend to actually build. This way, maybe you might just be able to keep vicious competitors from selling similar items. The inventors also disclose an embodiment where "the article is sock-like and the pocket is shaped to receive a foot."

Selected figures from US Patent 1,105,618

The upper right of the drawing demonstrates the ensoapification process. That word -- ensoapification -- is my own invention. The inventors did not use that word, but they could have. The patent office recognizes the fact that inventions may contain parts or involve processes where a word doesn't yet exist. So, they are pretty much cool with inventors who make up their own words, provided that the new words are defined. Making up words for patents is one of my favorite activities.

The diagram in the lower right shows how the wearable article and packaging for generating bubbles may be used. A simple whoosh of the hand (or foot, in an alternative embodiment) creates a plethora of mirthful frothy effervescence.

A patent must be useful

One of the requirements for a patent is that it must be useful. Generally speaking, it must solve a problem with the prior art. (Prior art has nothing to do with paintings made by Richard Pryor, by the way. Prior art is fancy legal talk for "stuff that has previously been described that relates to the invention".)

So, patents usually include some verbiage about how pitiful the previous inventions were. This patent is no exception. The inventors articulate not one, not two, but three woeful limitations to other bubble making devices.

1. "[O]ne typically gets the soapy liquid on oneself and ends up a sticky mess, especially on one's hands." Egads! How do you clean a soapy mess off your hands?!?!? You can't hardly use soap!!

2. "Also, most bubble wands have a single or very few holes in the distal (blowing) end, resulting in few bubbles being produced at a time." I readily acknowledge that my distal end has only a single hole for producing bubbles.

3. "[F]or small children or the otherwise inexperienced bubble blower, often it is difficult to find the right rate of blowing to achieve good bubbles: blow too softly and nothing happens; blow too hard and the soapy film collapses and nothing happens. It can be very frustrating." I can't even count the number of parties that I have been to that were ruined by inexperienced bubble blowers!

I'm sure all would agree that society is well served by this new invention.

But wait!

Some of you may have read my blog post about a patent issued to Amazon. Those of you who read this work of art will recall that the internet was absolutely furious that Amazon had been awarded a patent for something as obvious as a white background for a photograph. You will also recall that the actual patent was not nearly as broad as that. I explained in the blog post that you have to read the claims to find out what the inventor (or assignee of the patent) actually owns the rights to.

If you are looking for an opportunity to take advantage of a loophole, I suggest you take a look at the claims.

Claim 1 of the patent includes the phrase "said article being a glove or mitten and said pocket being shaped to receive a hand". Bear in mind that to infringe on a patent, you must transgress all of the recitations in at least one claim. If you omit even one part, you are not infringing.

Further, I should explain something about claims 2 through 14 of this patent. They are all dependent claims. Each of these claims includes by reference all the parts of the corresponding independent claim, as well as further limitations. For example, claim 1 requires a pocket which is shaped to receive a hand. Dependent claim 3 further requires that "said pocket comprises at least two finger portions".

Claim 1 is the only independent claim in US Patent 1,105,618. Claim 1 includes the requirement that the wearable article and packaging for generating bubbles must be a "glove or mitten ... shaped to receive a hand". Can you see where I'm going with this?!?!

I'm pretty excited about this loophole I found. Even though the inventors specifically mentioned using a sock on the foot instead of a glove on the hand, they didn't claim it! I am free to sell a wearable sock and packaging for generating bubbles! I don't know about you, but I am picturing a parade with a row of clowns walking on their hands, generating bubbles as they wave their feet at the adulant crowds.

Caveat: The freedom to sell swim fin bubble makers is based just on this patent. Before firing up the manufacturing facility, I strongly suggest doing a full patent search.

Why did they omit the sock?

Why did the inventors (or the lawyers for the inventors) not claim a bubble maker that could be put on your tushie so that it is activated when you shake your tail feathers?

The lawyers did their job. I had a look at the initial filing of the patent, which can be found in the file wrapper and is available online. Claim 1 in the original did not include any limitations about hands and gloves or mittens. It talks about a pocket being shaped to receive a body part.

The patent examiner, who serves as a referee to block patents that aren't quite up to snuff, also did his job. I haven't read the whole file wrapper, but I would guess that the examiner looked at the prior art, and came to the conclusion that the original claim was too broad, and that the inventors' lawyers responded by adding limitations until the patent examiner yielded.

I am actually familiar with one piece of prior art that was cited by the examiner. The picture below is from a design patent filed by Steve Jernander and Ardith Clubb.

From US design patent D292,641, Cap for bubble blowing

So you see that the idea of inserting a body part into a bubble generation device is not novel. That in itself is probably not enough to keep the bubble mitt from being patented. The original claim required "at least two films of liquid resistant material", which are "sealed on at least one common edge", and which are configured for "substantially preventing "the body part" from getting wet. Ideally, the examiner must find prior art that describes all the recitations in a given claim, and there are a lot of other parts to the bubble mitt claim. I am sure the examiner did this, but I am just too lazy to read through the whole file wrapper.

You may be wondering how it is that I would know about this bubble cap patent. I'm sure you noticed that the patent issued on my birthday, but the reason I knew of the patent is that Steve Jernander was a cousin of mine.


Disclaimer: Despite my apparent claims about actually knowing something about patents, I am not a patent attorney or agent. Or anything having to do with patents, to be honest. Nothing in this blog post should be construed as being legal advice. If you are silly enough to take something from this blog post as actual advice, then my liability is limited to the amount that you paid me to read the blog post.

A new color has been patented!

April 1, 2019, 8:38 am

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Milwaukee, WI. -- Rufus Chromaphile, spokesperson for John the Math Guy, LLC announced today the issuance of US Patent 10,244,600, assigned to John the Math Guy, LLC for a new color. "This patent represents a great leap forward for fashion, for design,  for art, and most important, for color science. John TheMathGuy has truly demonstrated thinking outside the rainbow on this one!"

When asked to comment, TheMathGuy explained the brilliant Aha! that led to this invention. 

"I was pondering about how it's not possible to stimulate only the M cones in the human eye. If you go to the edge of visible light at the infrared end, you can effectively stimulate only the L cones, and you will see red. If you go to the ultraviolet edge, you can stimulate only the S cones and see a lovely violet. Unfortunately, all visible light which stimulates the M cone (the one in the middle) will also stimulate the L or the S cones. What if we could see a color which only stimulated the M cones?"

TheMathGuy reasoned that he had to use light similar to ultraviolet and infrared to get this effect, but obviously it couldn't be either of them. The Aha! moment came when he started thinking about the compliments of these two colors, ultrared and infraviolet. He rushed to his lab to dig out a darkon generator (which generates anti-photons) and a monochromator (which isolates a single wavelength of light). After a quick trip to American Science and Surplus, he developed a way to combine ultrared and infraviolet.

The resulting color was so mind-blowing that it sent him to the emergency room, but not before he emailed a quick description to his patent attorney. 

The name of this new color? Ubergreen. 

Simulated Ubergreen

What city in Italy is the color magenta named after?

April 23, 2019, 10:20 am

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I have asked this question in my color classes, Inevitably, I get no answer, or answers like Rome? Venice? Flagstaff? I then ask some rhetorical questions: "When was the war of 1812?""Who is buried in Grant's tomb?""What is the color of a red dress?" and "Who is the greatest color scientist who ever lived?" This will often prompt one of the more adventurous students to take a wild guess at the answer to the magenta question. For the time being, I will keep you in suspense about the answer cuz I got a little story to tell.

Tyrian purple

The story starts around 1600 BCE with a special purple dye that has been made from the rock snail for several millennia. It takes a lot of these snails to dye all your hankies. Like, a lot of snails. Like jillions of the little guys. About a quarter of a million of these mollusks had to be sacrificed to yield one ounce of Tyrian purple dye. As a result the dye was incredibly expensive - it was literally worth more than its weight in gold.

But it was a distinctive color and it was fade resistant, so fabrics dyed with Tyrian purple were prized by people who had more money than they knew what to do with. Purple is thus associated with royalty. This association grew draconian in fourth century Rome, when no one but the emperor would be caught dead wearing Tyrian purple. Literally. The punishment for wearing Tyrian purple was death.

The rock snail (Murex bandaris), and Tyrian purple

The royalties purple fetish did not return until 1857 with the wife of Napoleon II, the Empress Eugénie de Montijo. She was the fashionista that all of France turned their eyes to. She fixated on purple, which was then available in one dye that was derived from lichen, and another dye called murexide, in homage to the Murex family of mollusks. It was not made from mollusks. We'll get back to that.

The industrial revolution ushered in a new form of affluence -- money and power that was not associated with family lines and land ownership. Entrepreneurs built factories that made stuff that people bought... enter a burgeoning middle class. With that middle class came the need for stuff to buy to show off one's affluenza. Since Kohler had yet to offer the Numi toilet (with Bluetooth and an intuitive touch-screen remote), that need had to be met by fashionable clothes.

Murexide

Noe, back to the source of murexide purple, as I promised. Murexide was first derived in the 1830's from the uric acid found in snake droppings. (Please try to avoid snickering at this. It is most unprofessional.) Apparently the commercialization of this was hindered by the unwillingness of snakes to produce sufficient quantities of excrement. It wasn't until the 1850's, when Europe was importing large quantities of the finest Peruvian bird poop (stop it!) for fertilizer, that would-be murexide producers found a source for the raw materials. Calling the raw material guano only enhanced the desirability of murexide.

A hard day's work in the guano mines

The beautiful color was lightfast (it didn't fade in sunlight like many dyes) but it unfortunately lost its color on exposure to the acidic air of urban life.  The burning of coal soured the air. Still, the European taste for purple had been whetted by bird poop. (I consider that last sentence to be my finest contribution to the field of chromo-scatalogical humor. Feel free to snicker at that.)

But all good times must come to an end. Sadly by 1881, books were being written about the end of the Golden Age of Guano in Peru [see Duffield, for example]. I should note that the decline in the guano market was not so much due to dwindling murexide production as it was the availability of cheaper commercial fertilizers that were locally grown. Modern day politicians should take note of the problems with basing an economy on guano.

"Excuse me Math Guy, what does this have to do with magenta?"
"Hang on, I'm getting to that."

Coal tar

I mentioned the burning of coal in connection with the downfall of murexide purple. In an example of "that which taketh away, also giveth", coal was to indirectly lead to the purples that replaced murexide. So, I may seem to be taking a detour to talk about coal, but trust me. It all ties together in the end.

A compound known as coke was being used to fuel the voracious iron smelting operations in England. Coal has lots of impurities, but coke is mostly pure carbon, so it burns faster and hotter than coal. It is manufactured by heating coal in an absence of oxygen. When it is heated, the carbon in the coal cannot burn due to insufficient oxygen. The impurities in the coal exit either as a gas (coal gas) or as a liquid (coal tar).

Coal gas is a mixture of flammable gases such as hydrogen, carbon monoxide, and methane. Around 1800, a fellow by the name of William Murdock hit on the idea of running the coal gas through pipes to places where it could be burned to produce light. In a792, his home in Cornwall was the first house to be lit at night with gas light. Making use of this byproduct of coke production soon became a business in its own right. By 1812 the British parliament chartered the Gas Light and Coke Company of Westminster, London as a utility company to provide coal gas for lighting.

So, a profitable use had been made of coal gas. How about the liquid byproduct? Coal tar (as one might guess from the name) is a thick black liquid -- the kind of thing you just want to dump into the river in order to make it someone else's problem. But it is also an organic chemist's playground, consisting of over 10,000 different chemicals.

Looking forward to a thick, rich cuppa Joe

Over the coming decades, curious chemists extracted a number of interesting organic compounds from coal tar, including naphthalene (1819), anthracine (1832), and in 1834, both phenol and aniline. I'm not going to get into the utility of the first two, but the latter two are relevant to this story because they could be turned into pigments.

In 1842, a process was discovered whereby nitric acid was added to phenol to create a yellow pigment called picric acid. This was a pretty color bu the pigment lacked commercial success since it was neither lightfast nor resistant to washing. It has found much better use as an explosive. And really, who doesn't want an explosive that has a pretty color?

Aniline, on the other hand, led to the development of many important pigments.

"You mean, like magenta?"
"Please be patient. I'm still setting the stage."

Mauve

1856 London. William Henry Perkin was a mere lad of 18 when he started experimenting with aniline in the hope of finding a way to synthesize quinine. Quinine is derived from the bark of the cinchona tree of South America, and was devilishly expense. It is used to treat malaria, and as a result, it is found in the ever-popular drink gin and tonic. British folks in India were known to contract malaria just to get treated with gin and tonics. But a wise man once said that the bark of the cinchona tree is devilishly expensive. Suffice it to say, a cheap alternative to the manufacture of quinine was a worthy goal for the young Perkin.

Two authors have commented on the naivete of Perkin in one of his experiments. Philip Ball has this to say:

[In one experiment] all he obtained was a reddish-brown sludge. Organic chemists quickly become familiar with this type of reaction -- generally it means the reagents have combined to give an unintelligible mess that is best flushed down the sink.

Garfield explains Perkin's naive tenacity this way:

Most chemists, particularly those trained by Hofmann at the Royal College, would have thrown the reddish-brown powder into a rubbish bin, and begun again.

But Perkin inquisitively continued this utter waste of time with aniline and arrived at a fabulous purple. He dyed a piece of silk with the chemical and was delighted by the brilliant color and the fact that it didn't readily fade. The image below shows sample of silk that was dyed by Perkin in 1860, and which now resides at the Smithsonian. Not Perkin; the sample of silk resides there.

Perkin initially dubbed his dye Tyrian purple, but later settled on mauve, which is the French name for the mallow flower. The chemical is also known as aniline purple, aniline violet,  mauveine, chrome violet, indisin, Perkin's violet, purpurin, rosolane, and violein. There is no dearth of invented words in the field of industrial color production.

The mallow flower

The timing couldn't have been better for Perkin. Remember how I cleverly mentioned the Empress Eugénie de Montijo and her purple fetish which was unsated due to the end of The Golden Age of Guano? In 1857, Queen Victoria wore a mauve gown to her daughter's royal wedding. Empress Eugénie expressed her delight that mauve matched the color of her eyes. The craze was so crazy that Punch magazine satirized the outbreak of "mauve measles". 

There is a lot more to Perkin's story, but it's time to move on to explaining how magenta got its name and how this relates to Italy. But first, we will talk about fuchsia.

"Stop teasing me and answer the question!"

"It's not about the destination. It's about the journey."

Fuchsia

Perkin's success with investigating coal tar sparked a fierce competition between colorists (chemists in the science of dyeing) in England, France, and Germany. They reasoned that there must be other brilliant colors hiding in the murky depths of coal tar. This hunch bore fruit of many colors. The general importance of coal tar in the production of dyes can seen by thumbing through Hurst's 126 page volume, A Dictionary of the Coal Tar Colors. That's right. A volume of 126 pages listing dyes made from color tar. A copy of this can be found on the coffee table of any reputable color scientist.

François-Emmanuel Verguin was one of the French competitors, who created aniline red in 1858. His choice for a color name was the euphonious fuchsine, after the fuchsia flower. In England, Edward Chamber Nicholson created the same aniline red in 1860 by a different process and named it rosein or roseine, presumably a rose by any other name.

Aniline red also goes by the name rubin or rubine, but I have not been able to track down the source, other than being derived from the Latin rubeus, meaning red. You got it. Someone called the dye red because it was purple.

Before I answer the original question, about how the color magenta got its name, I would be remiss to talk about fuchsia without pointing out that it is one of the most misspelled of all color names. Nathan Moroney ran an online color naming experiment for years. He had a website that would display some combination of red, green, and blue, and then ask the person to type in a name for the color. The pie chart below shows that there are three misspellings of fuchsia that are more common than the correct spelling: fuschia, fuscia, and fushia. Only 10% of three respondents spelled the word correctly.

But I digress. Let's return to the story, which is already in progress.

The Battle of Magenta

The Battle of Magenta, fought near Magenta, Italy, occurred on June 4th of 1859. This was a decisive battle in the Second Italian War of Independence. The French-Sardinian alliance, led by Napoleon III, won out over the Austrian forces. Yes. This is the same Napoleon II who was mentioned earlier for having a fashionista wife. An interesting coincidence, but unrelated to the question at hand.

The Battle of Magenta, by Gerolamo Induno

I will quote from three sources as to how this battle relates to the newly created dye, aniline red.

Philip Ball offered this explanation:

But the color became more popularly known as magenta, named in honor of the Italian town where the French army fought and defeated the Austrians in June 1859.

Ok... sounds good. But how did the dye get associated with the battle? Kate Smith's rendition:

The Battle of Magenta, fought on the outskirts of the town during the Second Italian War of Independence. Some historians say the Battle of Magenta was a turning point in the war. ... The color reminded someone – most likely the person who named it – of the uniforms worn by the Zouave troops of the French army.

Maybe this is the connection? But it begs the question about what dye was used for these uniforms, since the dye was brand new. And another thing that bothers me: I understand that the image above of the 160 year old painting painting as rendered on my computer display is not likely to be color accurate, but the color of the uniforms seems to be closer to red than magenta.

Victoria Finlay had a more practical take on the matter:

It's first name "fuschine" (from the reddish-purple flower fuschia) was too easy to mispronounce, and it got better sales when renamed after a battle that year in the town of Magenta in northern Italy.

Kassia St Clair has offered an even more business-savvy explanation. I have found no other evidence of her assertion that one of the first sales was to an army, but the explanation is compelling.

The first customers [of the dye], intriguingly, were several European armies, who used it to dye their uniforms. The names, though -- 'fuchsia' in France and 'roseine' in Britain -- would not do for so dashing and assertive a hue. Instead, it became known as 'magenta', in honour of the small Italian town where, on 4 June 1859, the Franco-Piedmontese army won a decisive victory against the Austrians.

So, the connection between the war and the dye is a matter of heated dispute. But one thing is clear. The name magenta was good product branding.

Solferino?

Hurst's Dictionary of the Coal Tar Colours lists one more name for the dye: solferino, but neglects to give a source for the name. I found this a bit confusing. The word reminds me of sulphur, which is yellow. Of course, it also reminds me of the purple sulphur bacteria. It would probably not be a good marketing move to name a sexy new dye after a type of bacteria. I can understand why this name didn't stick.

So, naturally, I started googling. I found out that Solferino is the name of another city in Italy. Oh? Interesting. I dug a bit further. It seems that there was a battle fought in Solferino, 20 days after the Battle of Magenta. Oh??? Isn't that interesting?!?!?!

Simon Garfield offers some explanation. The first time I read his account, I missed the fact that it is talking about two different names for the same color.

In Britain, it [aniline red] became known as solferino and then magenta, taking the names from the Franco-Piedmontese war against Austria and Garibaldi's victory in North Italy, where the dye matched the color of the soldier's tunics. 

Here is a different explanation from an online dictionary

After Solferino, a village in northern Italy, where the Battle of Solferino was fought on June 24, 1859, resulting in forty thousand casualties in a single day. The color was named so because the dye of this color was discovered shortly after the battle, and supposedly the color represented how the battlefield appeared after the bloodshed.

One one trivial correction - the dye was discovered shortly before the battle, not after. Another rather bigger error - blood is red, not fuchsia. Blood dries quickly to a dark brown. I don't find this a credible explanation.


My own best guess is that there was a large order of aniline dyes for military uniforms that occurred slightly after the Battles of Magenta and Solferino. Patriotism and the positive image of a winner became useful branding for the new dyes. Both town names were used, but magenta won out in the end, possibly because of the connotation of solferino with sulphur.

And that, my friends, is how the color magenta got its name.

Bibliography

Ball, Philip, Bright Earth, Art and the Invention of Color, University of Chicago Press, 2001

Blaszczyk, Regina Lee, The Color Revolution, Massachusetts Institute of Technology, 2012, pps. 21 - 44

Duffield, Alexander James, The Prospects of Peru: The End of the Guano Age and a Description Thereof, Newman and Company, 1881

Finlay, Victoria, The Brilliant History of Color in Art, J. Paul Getty Museum, 2014

Garfield, Simon, Mauve, How One Man Invented a Color that Changed the World, Faber and Faber Limited, 2000

Hurst, George H., A Dictionary of the Coal Tar Colours, Heywood and Company, 1892

Lunge, Coal-Tar and Ammonia, Gurney and Jackson, 1882

Meldola, Raphael, Coal and what we get from it: A romance of applied science, 1913

Moroney, Nathan, The many misspellings of fuchsia, from Colour Coded, Society of Dyers and Colourists, 2010

Smith, Kate, Italy | The Colorful City of Magenta,

Smithsonian Libraries, Making Color

St Clair, Kassia, The Secret Lives of Colour, John Murray Publishers, 2016, pps. 162 - 164, 167 - 171

The Red Velvet Cake Effect

May 17, 2019, 8:59 am

≫ Next: Where did my indigo? (part 1)

≪ Previous: What city in Italy is the color magenta named after?

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I recently stumbled upon a video this week where the speaker described experiments where the presence of color tricked participants into tasting flavors that weren't there. The idea seems preposterous. How can flavorless food coloring impart taste?

How Color Affects Taste, Prof. William Lidwell of University of Houston

As odd as this may seem, it must be true. I mean, I found another video on YouTube that makes the same general claim: "Soft drinks that are blue are considered to be more thirst quenching, whereas soft drinks that are pink are considered to be more sugary, even if they're not." There are not one, but two guys who are articulate, sound intelligent, and have the massive funding required to produce a YouTube video on this topic, so who am I to question their veracity?

The Taste of Color, Trace, for DNews

A little googling turned up similar results. For example, two manufacturers of color measurement devices have blog posts on the topic. Here is a quote from the blog post from Konica Minolta:

"In a study published in the Journal of Food Science, researchers found that people confused flavors when a drink did not have the appropriate color. A cherry-flavored drink manipulated to be orange in color was thought to taste like an orange drink, and a cherry drink manipulated to be green in color was thought to taste like lime."
How Color Affects Your Perception of Food

A blog post from HunterLab points to an important distinction between how color affects our expectation of taste and how color affects our perception when we taste. "[We] constantly evaluate foods based on their hue, from checking if the meat is still red to guessing an avocado is ripe when its skin becomes dark green."

The author goes on to say "Color is so powerful that [it] can override what our other senses are telling us to be true, causing us to taste sweetness that isn’t really there, experience flavors that aren’t present."
Examining the Science Behind Color Perception of Food Flavor and Quality

I'm going to invent a name for this phenomenon: The Red Velvet Cake Effect. The rich flavor of red velvet cake is is an olfactory illusion which is caused by the flavorless red food coloring. At least that's what my wife told me. Again, who am I to question?

Ok. Maybe that's not exactly true. The action of an acid (from vinegar or buttermilk) on natural cocoa imparts a red color to this cake, and this acid probably has an effect on the flavor. But pretty much all recipes for red velvet cake also include red food coloring. Why do this? The red food coloring in the cake tricks us into thinking that the cake is richer in flavor. Or maybe the cake really is richer in flavor?

These are not criticisms

Let me preface my next comments -- the comments about the aforementioned videos and blog posts. I don't mean for my comments to be criticism.

The first three of these reports are infotainment -- journalism targeted to inform and entertain. It is not expected that they go into details about how the experiments were performed. There is no talk of qualification of participants, a control group, accounting for the placebo effect, or the statistical relevance of the results. To go into such details would defeat the purpose of entertaining. Who wants to wade through boring details when all they want from the article is a factoid that they can share at the local tavern?

It's a little known fact that Cliff Clavin never actually said this.
It comes from a John the Math Guy blog post on vermillion.

Another shortcoming of the preceding infotainment  (with no criticism implied) is that none of the first three give specific reference to the experiments. Again, I am not being critical, but the articles don't offer a lot of help to the person who is a bit more than just curious. How can they find the technical paper on the topic?

Let me make this clear. I am not criticizing the first three. Infotainment is a great thing, and these are great examples of infotainment. But let's take them for what they are. Suppose you are president of the American Broccoli Growers Association, and I need to decide whether to fund research for a plant geneticist who wants to adjust the cruciferous color so as to make kids go wild about the taste of broccoli. You really need to research beyond the infotainment articles.

I commend the HunterLab article for moving from infotainment into the realm of edutainment. The article educates as well as entertains. There is a clear explanation of what experiments were performed and how they can be interpreted. And the technical papers and experts are identified so an interested reader can go out to find additional details.

But... I wonder if is there some selection bias in the choice of research papers that have been cited? Do other experiments confirm these conclusions? In true John the Math Guy style, I have done a borderline-obsessive amount of digging to get to the true flavor of this question, not colored by any preconceived notions.

Does the color of the food itself change the taste?

I followed the HunterLab link to an actual research paper from 1980. Here is what a quote from that paper:

"Results showed that color masking dramatically decreased flavor identification of fruit-flavored beverages, while atypical colors induced incorrect flavor responses that were characteristically associated with the atypical color. In addition, the color level of beverages had significant effects on their overall acceptability, acceptability of color and of flavor, as well as on flavor intensity."
Effects of Colorants and Flavorants on Identification, Perceived Flavor Intensity, and Hedonic Quality of Fruit‐Flavored Beverages and Cake

Only with a blindfold could Sherlock tell that all the glasses contained prune juice

Here is another research paper demonstrating that the taste of sweet beverages can be "flavored" by color.

"The results of the present experiment corroborate the findings of the previous experiments, demonstrating the influence of color on taste perception"
"... subjects in the present study were moved by the color stimuli to completely misjudge the flavor of the substance being tasted (calling the birch beer such things as "cherry soda" or "cream soda")."
The influence of color on the taste perception of carbonated water preparations

And yet another...
"Both the colour of the cider itself and the colour of the label significantly influenced perceived flavour and hedonic response to the ciders."
Cross-modal influence of colour from product and packaging alters perceived flavour of cider

Oh! I gotta get me some of that Hedonic Response Cider!

The only fruit-flavored beverage that I drink is wine, so I kinda don't care. The HunterLab article anticipated my predilections so they also mentioned a blog post of theirs that talked about color and wine. That second blog post summarized an experiment where researchers tried to trick professional wine tasters by adding flavorless red food coloring to white wines. The deceit was successful.

"A white wine artificially colored red with an odorless dye was olfactory described as a red wine by a panel of 54 tasters. Hence, because of the visual information, the tasters discounted the olfactory information."
The color of odors

My wife's favorite whine is "I want to go to Miami!"

It is a little known fact that olfactory means "relating to the sense of smell."

This was a bit of a disappointment to me, since I know that, all scientific research aside, I prefer red wines! I probably don't like Riesling, but I'm not sure. I've never riesled.

As you may expect, beer is also important to me. And I know that dark beer is way more better than a an icky sickly pale yellow pilsner. But if two beers differ only in color, does my eye convince my tongue and nose that the beer that is richer in color is also richer in flavor? I can't count the number of times that I have lain awake at night pondering that question!

Interestingly, experiments with beer haven't been as conclusive. The quote below is a bit complicated, but here is what I think it says: If someone is a Miller Lite kinda guy, they are more apt to be fooled by a little brown food coloring. I believe this, but only because it fits my preconceived notion that people who drink light beer are less sophisticated than I am.

"When the participants evaluated the expectations and tasting experience of the two different beers ... (pale vs. dark), after tasting, those who preferred pale beers, rated the darker beer as tasting sweeter than those who usually prefer other types of beers, such as dark ones..."
Dark vs light drinks The influence of visual appearance on the consumer's experience of beer

The Lovibond scale is used to assess beer color

One finding of the next experiment (below), is that before the mug comes to my lips, I expect that a beer with a rich brown color will be richer in flavor than a light yellow beer. Well, duh. The important part of this research is that when I actually taste the beer, my palate will not be fooled.

"Dark and pale beers were evaluated both before and after tasting. Importantly, these beers were indistinguishable in terms of their taste/flavor when tasted without any visual cues. The results indicate that the differing visual appearance of the beers led to clear differences in expected taste/flavor. However, after tasting, no differences in flavor ratings were observed, indicating that the expectations based on visual cues did not influence the actual tasting experience."
The Influence of Color on the Consumer's Experience of Beer

So, let's move on to chocolate, another place where I like to brag about my superior tastes. In my opinion, milk chocolate is for the hoi polloi. Having an affinity for dark chocolate shows that you have culture. But, at least according to this research, my false snobbery can be exposed with a little brown food coloring in the outer candy shell of an M&M. And even worse, just calling  the little rabbit pellets dark chocolate will fool me. Really? Am I that easily misled!?!?!? 

"The participants rated brown M&Ms as being significantly more chocolatey than green M&Ms and “dark chocolate”-labeled M&Ms as being significantly more chocolatey than “milk chocolate”-labeled ones."
The Influence of Color and Label Information on Flavor Perception

I like my chocolate just like my used motor oil - dark and flavorful

This sampling of research papers suggests that color can suggest taste, but that might not always be the case.

Does the color of the plate or cup influence the flavor?

I want to investigate a phrase from the cider experiments which I skipped over: "and the colour of the label". The cider house rules apparently extend beyond the color of what goes into your mouth. The effect on flavor of the color of the coffee mug seems to be fairly well researched. And the research seems to be heavily weighted toward verification of the Red Velvet Cake Effect. I have some quotes below.

"The results revealed that the colour of the cup exerted a significant influence on both pre- and post-tasting ratings for all attributes measured."
Cup colour influences consumers' expectations and experience on tasting specialty coffee

"... the coffee was rated as less sweet in the white mug as compared to the transparent and blue mugs."
Does the colour of the mug influence the taste of the coffee?

"The colour of the cup, for instance, has been shown to prime notions of sweetness (e.g., pink cup) or acidity (e.g., yellow or green cup) that may carry over to influence the tasting experience."

"Given that different styles/varieties of specialty coffee have different dominant/desirable qualities (e.g., acidity/sweetness), in the future, the design of coffee cups may need to be customized for different coffee drinking experiences (e.g., origin or roast), much as seen in the world of fine wine (with different glasses for different grape varieties)."
Assessing the influence of the coffee cup on the multisensory tasting experience

Choose your cup wisely, it will affect the taste of the coffee

Seems pretty conclusive that the Red Velvet Cake Effect extends to coffee mugs. But are pastries on plates any different from red velvet chocolate? Apparently so.

"[No] main effects of the plate colour on the evaluations of greasiness, crunchiness, creaminess, and sweetness [of pastries], as well as the hedonic value and purchase intent in stage 1 and stage 2 could be found."
Visual merchandising of pastries in foodscapes: The influence of plate colours on consumers’ flavour expectations and perceptions

But the color of the plate has a clear effect on the sweetness of strawberry mousse.

"Specifically, we investigated the influence of the color (black or white) and shape of the plate on the perception of flavor intensity, sweetness, quality, and liking for identical strawberry mousse desserts.The results demonstrated that while the color of the plate exerted a significant influence on people’s perception of the food, the shape of the plate did not. In particular, when the mousse was served from a white plate, it was perceived as significantly more intense and sweeter, and was also liked more."
Is it the plate or is it the food? Assessing the influence of the color (black or white) and shape of the plate on the perception of the food placed on it

Choose the plate wisely if the dessert is red velvet cake or strawberry mousse,

leave the ugly plates for pastries

I'm not sure what to make of all this. I am getting a bit peckish for dessert, though.

Survey papers

This limited research has led to some conflicting conclusions. I have browsed through a dozen papers and found that most (but not all) confirmed the Red Velvet Cake Effect. I readily admit that my sampling of technical journals on flavor science has not been thorough. Basically, I have only earned my associates degree in Velvet Cake from Google University. In particular, I would expect that my research would be biased in favor of papers that support the surprising results.

It is a little known fact that red food coloring might be made from Hemipterates (the order of true bugs, in the class Insecta) like the cochineal or kermes vermilio, but that Starbucks has pledged to stop using the natural dyes that are made from insects.

To get a better perspective, I will have a look at scholarly review papers.

Charles Spence (from Oxford) is a prolific author on the Red Velvet Cake Effect. (I say this despite the fact that he has not, to my knowledge, used this phrase. I am sure he will start using it when he reads this blog post.) Here are a few of his papers which provide an overview of a little bit of the research that he has reviewed. When I say "a little bit", I mean... well... the first paper has about three pages of references. The second one has 170 references. I should live long enough to read that many research papers.

Does Food Color Influence Taste and Flavor Perception in Humans
On the psychological impact of food colour
Background colour & its impact on food perception & behaviour

Spence (In his paper "Does Food Color...") makes the following statement:

"Does food coloring influence taste and flavor perception in humans? Although researchers have been investigating this important (both on a theoretical and practical level) question for more than 70 years now (see Duncker 1939; Masurovsky 1939; Moir 1936 for early research), an unequivocal answer to the question has not, as yet, been reached."

Ahhh... that explains the confusing results that I found! Then he goes on to burst my bubble.

"That, at least, would seem to be the conclusion drawn by the majority of researchers in the field."

Slicing the onion thinner

When I asked her for the color of the car, she said it was the color of an onion

Anyone who has passed an intermediate level course in "how to lie with statistics" will recognize that the answer you get depends a great deal on the precise phrasing of the question. There are a number of different but related questions that a Red Velvet Cake Effect experiment could address:

1) Does the color of the food influence my expectation of taste before I sample the food?

2) Does the color of the food influence whether I can correctly identify a given food?

3) Does the color of the food influence my assessment of the intensity of the taste of the food (the gustatory effect)?

4) Does the color of the food influence my assessment of the intensity of the flavor of the food (the olfactory effect)?

Wait... Aren't 3) and 4) the same question? Maybe to you and I taste and flavor mean the same thing, but to people who are really into the science of taste and smell, there is a distinction. Taste is the thing that we do with our tongue when we are not sticking out at people we dislike. We can distinguish only four distinct tastes with our tongue: sweet, sour, bitter, and umami (which means something like savory).

I never developed much of a taste for relativity

Flavor, on the other hand, is detected in the nose. To make things even more complicated, this olfactory (smell) component might be administered orthonasally (though the nose, as when someone pretentiously sticks their nose in a wine glass to detect the nose of the wine), or it may be administered retronasally (through the mouth, like when you take a sip of the wine).

The nose of a wine is best sensed in near silhouette conditions
with clouds and mountains in the background.
Pretentiousness is accentuated by an "I forgot to shave for the past four days" beard.  

As an aside, a true oenophile (which is French for priggish wine snob) will tell you that the best way to tell the nose of a wine is to take a sip, spit it out, and then exhale through your nose. This is an example of retronasal olfaction. A true Wisconsinite like myself would be aghast at the thought of spitting out something that contains alcohol.

Now, how did Spence answer the four questions?

Spence summarized one experiment having to do with the first question. British and Taiwanese participants were asked what they expected a colored beverage to taste like. The Brits overwhelmingly (14 out of 20) expected a brown beverage to taste like cola. None of the 15 Taiwanese participants expected a cola taste - grape, mulberry, and cranberry were their choices. So, the answer to the first question is "yes", but the expectation is culturally dependent.

According to Spence, the answer to the second question is unequivocal. Color influences identification of foods.

According to Spence, the experiments that address the third question do not give consistent results. According to me, the combinations (which colors have an effect on which of the four tastes) is confusing.

According to Spence, the answer to the fourth question is clear cut. Color does flavor our sense of flavor.

Charles Spence, Food Scientist

So, I conclude that the two videos and two blog posts mentioned way back at the start of this blog post are pretty decent in their portrayal of the science behind the Red Velvet Cake Effect. They didn't quite catch all the nuances and slightly contradictory results, but we can't expect everyone to produce blog posts that are as long and boring as this one!

If you have read up to this point, I leave you with a well deserved factoid: The flavor and taste of red velvet cake is most likely due (at least in part) to the red food coloring, which might be manufactured from bugs.

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Where did my indigo? (part 1)

August 5, 2019, 9:38 am

≫ Next: The allure of tweeny colors

≪ Previous: The Red Velvet Cake Effect

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I answered a question on Quora recently. I am so proud of my astute answer that I decided to expound on it to make it into a blog post.

The question: What is the true color of indigo?

In today's blog post, I provide the first answer to that question.

Dyeing is a pigment of my imagination

The words dye and pigment are often used interchangeably. Just don't try that in the presence of any colorist. At best, they will roll their eyes and/or laugh at you.

Cool pic of dyes from Alliance Industries

The general term is colorants, something that is used to impart color. Dyes and pigments are two types of colorants.

Dyes are molecules (often organic) that are incorporated into fibers. As a rule of thumb, they are soluble, and we work with them typically in solution, so they are individual molecules. Also generally they require a binder molecule to attach them to whatever we are dyeing. Dyes are most commonly used for dyeing fabric. Dyes need to penetrate into the substrate (e.g. the cloth fibers) in order to become permanent.

Pigments are made from grinding stuff up -- usually non-organic compounds. Since they are ground up, they come in the form of solid particles with lots of molecules clumped together. when used, they are generally suspended in a vehicle that is evaporated when the paint or ink dries. The vehicle might be water (as in latex paints and inkjet inks) or oil (oil-based paints and lithographic ink) or a solvent such as alcohol or toluene (sometimes used in gravure printing ink). Pigments generally coat the substrate rather than becoming incorporated into the substrate.

I expect everyone to use these terms correctly from now on. This will be on the final exam.

Mordant or less?

When I was young, I remember my sister showing me a neat trick. She showed me how to crush the flower buds of a certain flower between my fingers. The flower excreted a gorgeous rich blue fluid. My sister told me that this was a dye used by Native Americans.

Naturally, I was scolded. Maybe my mother was angry because the fluid stained my hands. More likely, she was angry that I stained my clothes. Then again, maybe she scolded me because I was destroying her irises. But, my memory is hazy. Maybe it was a wildflower. And maybe the Native American dye that my sister told me about was beets. I dunno which version is true, but one fact is perfectly clear. It was Nancy's fault. She forced me to get into trouble. This last part will be on the final exam.

This all left me with the impression that dyeing was pretty easy. You find some natural color in the woods or in a field. You crush the plant, dissolve it in water, and then soak your cloth in it.

Indigo dye is almost that easy to use. You just soak the cloth in a solution of the dye, rinse it, and then dry the fabric. Well, maybe that's a simplification, but I think I have the basics of it.

But making the dye is a bit more involved. The indigo plant has pretty pink flowers, but that's not where the dye comes from. Oddly enough, the dye is made from the leaves. These leaves are mashed and then fermented. The gunk left over is then dried and beaten to aerate it, since the process needs oxygen. Then it is left to dry into cakes.

When I first heard this, I was surprised. Who'da ever thunk to ferment leaves? Who'da ever thunk to ferment something and then not drink it? That part boggled my mind. (I'll get back to that in just a bit.)

Getting back to the dye, indigo is odd in the world of dyes. Indigo is called a non-mordant dye, because it does not require a mordant.

Ok, so what's a mordant?

Most dyes do not have a natural affinity for cloth. That is, they don't stick. Cloth is treated with mordants (like alum or tannic acid) so that the dye molecules will stick. The mordant molecules have an affinity for both the cloth and the dye, so they bind dye molecule to cloth by linking the left arm to one and the right arm to the other.

Here is the lesson that will appear on the final exam: Indigo was one of the earliest dyes because of two properties. First, the dye is created naturally in a way that humans could readily see and imitate. Second, the dye did not require pretreatment of the cloth to fix the dye.

Who invented indigo?

Indigo comes from the the indigo plant, specifically from the species of the indigo plants named indigofera tinctoria and indigofera suffruticosa. I called up the ancient Roman historian, Vitruvius, to help answer the question of who invented indigo dye. He told me that "indigo comes from India... where it attaches itself as mud to the foam of the reeds." Hence the name, indigo, which is derived from the Latin word indicum, meaning substance from India.

Now I can understand how someone would have come up with the idea of fermenting indigo leaves. I surmise that someone noticed that the muddy foam on the indigo plant stained fingers and cloth. They then sought to duplicate the natural process, and likely found that they needed a bit of this sticky foam as a starter. Whatever animicula was in the foam -- maybe it was yeast? -- would greedily ingest something in the leaves and go through some sort of chemical reaction that liberates the indigo dye molecules.

A bit of historical pedanticness -- just which Roman historian I spoke with is a matter of disagreement among historians. The quote above is from Ball, p. 201. Another account (Phipps) refers to Pliny, without a fancy quote. Another author, DeBonnet, attributes a similar quote to Dioscorides in 23 BC. I am not really sure who I talked to on the phone. I had spent the whole night sampling my fermented indigo, and ... well...

Marco Polo brought this dye to Europe from his travels in India. Indigo dye became a much desired item for import from India to Europe, first along the Great Silk Road, and then around the Cape of Good Hope. For example, Dutch ships carted nearly 170 tons of the dye from India to Europe in 1631. This factoid will not appear on the final exam.

Cool picture of the indigofera plant, from Phipps, 1832

I pause here to admit to a gap in my personal recollection of world history. I'm a bit surprised that the ancient Greeks had trade routes going with India. Here I thought Marco Polo was the guy who first connected European commerce with Indian commerce. Did I sleep through that day in history class?

So far, the story goes like this: The recipe for making indigo dye from the indigofera plant was devised in India, which became the source of indigo dye in Europe. There are reports of indigo dye in Harappan Civilization in the Indus valley somewhere around the time 2,000 BCE, so this all makes sense.

But that's only part of the story. A clay cuneiform tablet, dating back to 600 or 500 BCE, was found in southern Iraq with the recipe for creating indigo dye.

Tablet housed at the British Museum

This is a bit of a conundrum having to do with the history of indigo. Suppose you were transporting indigo from India to Babylonia. Would you load your camels or rafts or what-have-you with bundles of leaves, or would you load up with cakes of the processed dye? I'm thinking I would go with the more compressed form. Keep up with me now... so if we have an ancient Babylonian tablet, written in ancient Babylonian cuneiform, that was found in the area that was ancient Babylon... and that tablet gives a recipe for turning indigo leaves into indigo dye...

Do you see where I'm going here? Why would a Babylonian go to the trouble of describing he process to manufacture indigo dye to a Babylonian when Babylonians are only receiving shipments of the rocessed dye???!?

I think that the indigo plant may have been cultivated in ancient Babylon. I think that indigo seeds were transported from India to Mesopotamia at some point before 500 BCE. Then again, maybe the seeds went the other direction at some time before 2,000 BCE?

Here's another indigo sighting from about that same time period. Herodotus (a Greek historian from about 450 BCE) wrote that in Caucasus "They have trees whose leaves possess a most singular property: they beat them to a powder, and then steep them in water; this forms a dye which they paint figures of animals on their garments." Herodotus doesn't actually use the word indigo, but it sure sounds like he was talking about how to make indigo dye. He also doesn't mention India. Strange.

So, now I'm confused about whether the process to manufacture indigo dye actually came from India.

Let's muddy the waters a bit more. In ancient Egypt, mummies were wrapped in linen. The strips of linen were dyed with indigo. This puts the invention of indigo back to around 2,400 BCE, and perhaps earlier. Did the very ancient Egyptians get their indigo from India? Or did the Indians get their indigo from Egypt? Were there even trade routes between these civilizations at that time? Tell me, just where did the indigo?!!??

There are also early reports of indigo dyes being used in the Xinjiang province of China around 1,000 BCE. Were there trade routes between China and India? Here my meager world history completely falls on its face. I done got edicated in 'murica. We don't need no stinking urapean history there.

Earliest occurrences of indigo dye in various regions of the Old World

I look at the map above, and it seems likely to me that indigo dye was developed independently in Egypt and India, and possibly also in China.

But I omitted one last piece of the puzzle. Indigo dyed fabric was found in scraps of cloth in Huaca Prieta, Peru that date back as far as 5800 BCE! I hope you're as excited about that as I am.

My conclusion: a process to extract indigo dye from the indigofera plant was developed independently in multiple places around the globe. That will be on the final exam.


Stay tuned for part 2 of this series of blog posts, where I investigate Isaac Newton and the indigo that he put in our rainbow!

Want to know more about pigments and dyes?
Have a look at a blog post about mauve, Tyrian purple, and magenta.
Or, check out the blog post about the invention of Klein blue.
Or better yet, have a quick read about vermilion and cinnabar.

Bibliography

Ball, Philip, The Bright Earth, Art and the Invention of Color, University of Chicago Press, 2001

Beloe, William, Herodotus, Translated from the Greek, 1814, p. 254
https://books.google.com/books?id=-6sCAAAAYAAJ&pg=PA254&lpg=PA254&dq=herodotus+indigo&source=bl&ots=DyKZWua1TA&sig=ACfU3U3r-EdOPzBCnicfxexVFzz2j0_qFA&hl=en&sa=X&ved=2ahUKEwiinZjvzunjAhUPiqwKHXQsDjMQ6AEwEHoECGIQAQ#v=onepage&q=herodotus%20indigo&f=false

DeBonnet, Maurice, Origin of Paint Pigments, Varnishes, Vehicles, National Painters Magazine, Vol 48, Jan. 1921, page 26.

Finlay, Victoria, The Brilliant History of Color in Art, Getty Publications, 2014

Mattson, Anne, History of Indigo in the Early Modern World,
https://www.lib.umn.edu/bell/tradeproducts/indigo#s5

Nassau, Kurt, The Physics and Chemistry of Color, The Fifteen Causes of Color, John Wiley and Sons, 1983, p. 285

Phipps, John, A series of treatises on the principal products of Bengal, 1832

Splitstoser, Jeffery C., Tom D. Dillehay, Jan Wouters, and Ana Claro, Early pre-Hispanic use of indigo blue in Peru, Science Advances  14 Sep 2016: Vol. 2, no. 9,

St Clair, Kassia, The Secret Lives of Colour, pps. 189 - 192

Wikipedia, Indigo, https://en.wikipedia.org/wiki/Indigo

Wild Color, History of Indigo & Indigo Dyeing,
http://www.wildcolours.co.uk/html/indigo_history.html

The allure of tweeny colors

August 18, 2019, 12:51 pm

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I recently saw an interesting question on Quora about colors that are positioned between the basic colors. Here is the question, and the answer I gave.

Question: “Why are those color hues so intriguing that linger right between two known colors: between blue and gray, between pink and purple, etc.? They keep me captivated with the visual ‘tease’.”

Interesting question! I have seen this before, and my own observations are that these tweeny colors are interesting and either beautiful or ugly because of this. I don’t know if I have the answer to why, but I have one plausible explanation.

Basic fact #1: There is much information compression and loss of information as an image makes its way from the retina to the upper parts of the brain. If I look out on the room before me, and then close my eyes to attempt to remember what is there, I come up sadly short. I won’t remember anywhere near all the objects, or remember much in the way of details about them. I certainly wouldn’t be able to paint a picture from memory (even if I could paint).

Basic fact #2: There is evidence that colors work the same way. When the lower brain tells the upper brain that a car is red, it doesn’t report the exact color coordinates of the color either an an RGB value or a number from a color matching book. According to the theory, it will generally put the color of the car into one of a small number of buckets. There might be eleven buckets, or maybe there are just a few more.

I suspect you may be inclined to disagree with such a small number. Surely there are hundreds or maybe thousands of nameable colors? The small number in the last paragraph comes from an experiment where people were shown a color and moments later asked to pick that color out of a lineup. This experiment showed that our remembrance of a color skews toward a quintessential version of that color family, and there are not hundreds or thousands of color families. A somewhat desaturated blue is remembered as blue. A slightly orange version of yellow is remembered as yellow.

Here is my blog post on the experiment: How well do we remember color?

This explanation is consistent with the way we perceive the world. I look at a car and say that it is red, completely ignoring the fact that one part of the hood is lighter because of the position of the Sun, and the lower door panel is darker because it is partially shaded. In some areas of the car, there is a strong delineation in color, and I can easily choose to be conscious of that. In other places, the change in shade is gradual enough that it is difficult to be consciously aware of it.

Let’s apply this knowledge to your question. Consider looking at a car that is somewhere between blue and gray. I may glance at it once, and my lower brain will decide that the color is in the gray family. I look again, and my lower brain may change its mind and put the color in the blue family when it reports to the higher brain.

If this happens, we have a cognitive dissonance - the upper brain has to deal with two conflicting thoughts: “the car was gray” and “the car is now blue”. This conflict draws our attention to the color, hence it is interesting.

Creating a circle that goes through three points on your lawn

August 22, 2019, 12:34 pm

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I get some off-the-wall questions once in a while. Today, I got an off-the-porch question and decided the answer might make a good blog post. I'm probably wrong about that, but here goes.

My friend Dark Laser (I have changed his name to protect his identity) is putting a flower garden in his backyard. He wants the edge of the flower bed to be a circular arc that goes through three points . Those three points have been defined by a higher power. Maybe the higher power is his wife, or maybe it's just cuz of where the house is. I dunno. Below is the drawing that he sent me.  I hope you appreciate his obvious artistic skills.

Before he sent the email, Dark did a little googling and YouTubing. He came up with one answer in a YouTube video, which I show below.

I'm not sure how to interpret an email that asks me a question, and also sends me the answer. I'm not sure what he meant by this juxtaposition of Q & A, but due to my insecurity, I took the email as a challenge. "See if you are as smart as this guy, John!!" I am certainly not going to allow any dufus on YouTube to out-answer me on any dumb old math question!

The MathTuber who answered this question used analytical geometry, which lies between geometry (which is all lemmas and compasses) and algebra (which is all factor this polynomial and take the square root of both sides). But mostly the video is algebra.

Here's my opportunity to show off my brilliance. The abracadabra algebra video is all well and good, but it doesn't completely answer the original Dark question. I mean, how does Dark use this equation? Does he need to go out and buy a huge piece of graph paper to lay on his lawn?!?!?

I chose to forego the algebraic approach and go for a solution that is more along the lines of Euclid and his book Elements. A lot of this ancient text has to do with making constructions of various figures with a pencil, a compass, and a straight edge. But I don't think Dark has these tools, especially not in the size required to lay this out on his lawn. So, I improvised with more appropriate tools: rope and stakes.

(While I am at it, let me take a moment for more self-congratulations. Pure mathematicians are perfectly content with theoretical answers. But I am an applied mathematician, which means that my math isn't happy until it answers a real world problem. You can't get any more practical than building an aesthetically pleasing flower bed!)

Step 1

Put stakes at Points 1 and at Point 2. Make two equal lengths of rope, and tie them together at one end. You don't need the ropes to be red and blue, as in my diagram, but it may help.

Tie the other ends of the ropes to the stakes at Point 1 and to Point 2. Grab the ropes where they join and pull them taut. Place a third stake at that point. This third stake is shown as a blue circle in the drawing below.

To avoid any confusion, I use the word stake in a general sense. If any of the stake positions should happen to be on lawn then a tent stake could meet the purpose. If the point is on a wood porch, then a hefty nail or a bolt could work. If the point is on a cement slab of a porch, then maybe a can of spray paint could be used to mark the point. Or a bathroom plunger? 

Step 2

Shorten the two ropes and repeat the process to locate a position for a fourth stake, as shown below as a second blue circle.

Now the aha! part, which I mention in order to create a sense of making progress. All circles which go through both Point 1 and Point 2 will have a center someplace on the blue dotted line! I hope you are as excited as I am.

A practical comment -- If the lengths of the ropes in Steps 1 and 2 are very close to the same, then the two stakes will be pretty darn close together. This is not such a good thing. This will lead to uncertainty in the angle of the blue dotted line, which will lead to inaccuracy in the position of the final circle.

An even more practical comment -- As I wrote that last comment (the so-called  practical comment), it occured to me that in Step 2, you could have kept the rope the same length, and merely pulled it to a position above Points 1 and 2. Too bad you already went through the process of shortening the ropes.  

Step 3

If you want to get technical on me, Step 3, is really two steps. It's a repeat of Steps 1 and Steps 2, only with different points. Repeat Steps 1 and 2 with Points 2 and 3. You probably will need to stretch the ropes out if you already cut them.

The green dotted line in the drawing below is analogous to the blue dotted line. All circles which go through both Point 2 and Point 3 will have a center someplace on the green dotted line! 

I know some of you may have jumped right ahead to the big climax, but I will state it here for anyone who might not have quote caught the significance: All circles which go through Point 1, Point 2 and Point 3 will have a center at the intersection between the blue dotted line and the green dotted line. Assuming the two dotted lines intersect, and assuming the two dotted lines are not along the same line, we have uniquely defined the center of the circle.

Step 4

A pure mathematician would stop at Step 3, since the point has been theoretically defined. But an applied mathematician, being of a superior breed, would realize that we still need a way to mark that physical intersection point on the porch.

Here is my suggestion. Place a skinny pole at a possible location for the circle center. Move the skinny pole around until it lines up with both of the blue stakes. Then turn your head and line the skinny pole up with the two green stakes. Then go back to the blue stakes to make sure they still line up. This may take several iterations. (My own experience suggests that copious quantities of beer can reduce the number of iterations necessary, not because beer increases your skill level, but because it gives you a more realistic view of just how important the position of the center of the circle is in the grand scheme of things.) Put a nail or a stake or a plunger at the point of intersection. 

If neither nail nor stake nor plunger will work on the porch, then buy another 12 pack and set it next to the intersection point. When a neighbor stops by to see what you're doing, hand him a beer and ask him to sit at the intersection point. The extra beers will keep him from moving.

A comment for those who remembered taking geometry... The task of finding the intersection would have been done with a straight edge. If Dark happens to have a 2 X 4 that is long enough, he could certainly use that to mark the dotted lines. A can of spray paint could serve to make that line indelibly, so the next owners of the house can appreciate the mathematics that went into constructing the flower bed. I haven't looked in Dark's garage lately, but I am guessing that finding a 2 X 4 that is long enough is a tall order. Or a long order. So, we must resort to an iterative procedure which would have been scorned by Euclid. But being scorned by Euclid is not a big deal. We are using non-Euclidean geometry.

Step 5

We're now ready to finish the project. Attach a rope to the nail/stake/plunger/neighbor at the center, and stretch the rope out until it reaches Point 1, Point 2, or Point 3.

Tie a spike to the  rope at that point. Holding the rope taut, move the spike from Point 1 to Point 2 and then on to Point 3, scratching the lawn to indicate the edge of the circle. If you are not skilled in the art of lawn scratching, feel free to tie a can of spray paint to the rope. I suggest a color of paint which is different from that of the grass. Although I show purple in the drawing below, green paint would provide a real good contrast to the color of my lawn.

Step 6

Pull up a lawn chair and finish the beer, content in having accomplished a good day's work.

Where did my indigo (part 2)

August 27, 2019, 7:00 am

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I answered a question on Quora recently. What is the true color of indigo? There are many answers to this question. In my last post, I gave one of them: indigo is a dye. This blog post expounds on Isaac Newton's answer.

ROYGBIV
We all know the seven colors of the rainbow: ROYGBIV. For those who missed that day in kindergarten, this is an acronym for red, orange, yellow, green, blue, indigo, violet.

But, what slice from the rainbow does indigo get? I consulted my high school optics book, Hardy and Perrin. It told me that indigo is the slice from 446 to 464 nm.

Question answered! Indigo is a very specific slice from the rainbow, which has been scienterrifically defined. 👍

But there is more to the story
But, as you might expect from my blog posts, there is more to the story. I didn't mention that this reference book, Hardy and Perrin, was from 1932. I also didn't mention that I had to dig deep to find this definition in any physics textbook. Perhaps I am being just a tiny bit disingenuous by implying that the definition "446 to 464 nm" is today's scientific consensus, when practically every science textbook I could find neglects to define indigo?

I dug my handy monochromator out of the closet and dialed in 455 nm. This is the location smack dab in the middle of the range that Hardy and Perrin gave for indigo, so that should give me the truest indication of what indigo is.

I looked at it and said, "Oh. It's blue." I asked my wife (who claims to be the most color-literate person who I know) what the color was. She said "blue", and then modified it to "cobalt blue", and then pointed at a lovely flower vase of hers. "Did you notice that there aren't any flowers in my cobalt blue vase?" She smiled and batted her eyes. I'm not sure what she meant by that.

I took a picture of the monochromator output with my cellphone camera. There are lots of caveats here, like RGB cameras don't do a good job at measuring color, and computer monitors don't always produce reliable color, but it kinda looks like my camera is identifying 455 nm light as blue.

Hmmmm... Who had the crazy idea of naming that part of the rainbow indigo? Why not just call it blue?

Newton's rainbow
To answer my rhetorical question, Isaac Newton was the person who had the crazy idea of naming part of the rainbow indigo. In 1665, Isaac Newton took leave from his schooling in Cambridge in order to escape the Great Plague. His work over the next two years proved to be one of the most productive in the history of science. Beyond the whole bit about the inverse square law of gravity, and inventing calculus to do that, Newton made some fundamental observations about light during his sojourn.

He passed sunlight through a prism and demonstrated that, among other things,

       white light is comprised of a whole lot of different flavors of light,

        a prism doesn't impart color to the white light that passes through (as was thought at the time), but rather bends light by different amounts depending on the flavor, and

        these individual flavors could be recombined to make white, or to make a host of other colors if some of the flavors are left out.

This remarkable time period is when he labelled the parts of the rainbow, or rather, the parts of a spectrum projectected on a wall through a prism. The results of his experiments were published by the Royal Society in 1672. These results challenged some long-held notions about light and color... but that's a good topic for another blog post.

Blue vs. blue
This may sound like a change of topic, but bear with me here. In English, there are eleven basic color terms (BCT): white, black, gray, red, orange, yellow, blue, pink, brown, and purple. I have written about these before when I tried to identify unambiguous color names. These basic color terms have been the subject of much research since the work of Kay and Berlin.

I offer a quote from a brilliant scholar, one who I respect immensely. I just can't say enough about the guy. Here is the quote from the esteemed John Seymour in his blog post How well do we remember color?

"In some languages, such as Russian, Japanese, and Italian, there is a separate word for light blue which stands on its own as a distinct color."

I have another quote, this one from a guy who is actually a real chromolinguist. Again, I respect him immensely. This is from Dimitris Mylonas

"[Two studies]  found that Russian and Greek languages both have 12 BCTs, differentiating ‘light blue’ from ‘dark blue’."

In Russian, we have two monolexic (single word) names for blue: синий and голубой, which mean "blue" and "sky-blue", respectively. In Japanese, the same concepts are in the words kon and mizu.In Italian, there is blu and azzuro. In Greek, kyaneos refers to dark blue, but it could also mean dark green, violet, black or brown. The ancient Greek word for a light blue is glaukos.

Consider the plight of Isaac Newton when he was trying to assign names to the colors of the rainbow. He looked at this wide expanse of colors which slowly pass from violet to green. If he had been conditioned by being a native speaker of Russian, Japanese, Italian, or Greek, then it may have been obvious to him to call the colors violet, dark blue, light blue, green, and so on.

But Newton spoke English. He did not have basic color terms for the two different types of blue. He had three choices.

1. He could use the terms dark blue and light blue. He probably felt this was kinda dorky. Or at least awkward. Or maybe he just wanted all the color names to be monolexic.

2. He could have chosen blue for the dark blue and found another name for light blue. I don't know what color names were in vogue at the time, but today, he might have used: aqua, aquamarine, azure, baby blue, cerulean, cyan, robin's egg blue, sky blue, teal, or turquoise. But these all strike me as being somewhat ambiguous.

3. He could have instead chosen blue for the light blue, and then found another color name for dark blue.

Newton went with option #3, and chose indigo as the name of dark blue. Here is a quote from Newton:

"So there are two sorts of colours: original and simple colours and colours made by compounding these. The original or primary colours are red, yellow, green, blue, and a violet-purple, together with orange, indigo, and an indefinite variety of intermediate shades."

Why did he pick the word indigo? I have a suggestion that I am dyeing to share. If I may be so bold as to quote the blogger who wrote the first post in this series: "Dutch ships carted nearly 170 tons of the [indigo] dye from India to Europe in 1631." Newton did his work with prisms in 1665. Indigo dye was quite popular in Europe at this time. So (my contention) is that the word indigo was at the time associated with a dark blue dye and that it was a common word at the time.

So, indigo is just another name for blue, only bluer than blue can be.

But, why didn't Newton just call them both blue? Why not just six colors for the rainbow? That is the thrilling question I will answer in my next blog post on this subject!

Bibliography
Brent Berlin and Paul Kay, Basic Color Terms: Their Universality and Evolution, CSLI Publications, Stanford, California (1999)

Arthur C. Hardy, Arthur C.  and Fred H. Perrin, The Principles of Optics, McGraw-Hill Book Co., Inc., New York. 1932, p. 16
https://archive.org/details/ThePrinciplesOfOptics/page/n29

Dimitris Mylonas and Lindsay MacDonald, Augmenting Basic Colour Terms in English, Color Research and Application, Volume 41, Issue 1, February 2016

Isaac Newton, A New Theory of Light and Colours, Transactions of the Royal Society, 1672

John Seymour, How well do we remember color?, John the Math Guy blog, May 30, 2018
https://johnthemathguy.blogspot.com/2018/05/how-well-do-we-remember-color.html

Why are Bermuda onions called "red" onions?

September 10, 2019, 7:00 am

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Quora often provides me with suggestions for blog posts. I read a question today that filled me with such indignation that I had to answer it, and had to post this to my blog as well.

Question: Why are 'red onions' called so when they're clearly purple in color?

Bermuda and Spain

Oh! The injustice!! I get angry with misplaced apostrophes, and livid when someone gets all floofy in the spelling of there/their/thay're/thare. But this is more than just word injustice -- this is about color. Anyone who knows me knows that color and beer are the most sacred things in my life.which is as close to being sacred to me as beer is.

But I digress. There is actually a very reasonable answer to this question, and oddly enough, it's one that doesn't require me to call anyone stupid.

In 1969, two linguistic researchers [1] asked a whole lot of people from around the world to name colors in their native language. Altogether, they surveyed a few thousand people, speaking 110 different languages. Based on an analysis of their data, they proposed the theory that languages follow a distinct pattern in the development of color names.

Primitive languages start with analogs of white and black with everything that is a light color being called white (or their word for white), and everything that is a dark color being called their word for black.

Red is the next color that is added, with a single word standing for red, yellow, orange, pink, etc. The next step after red is either to create a new word to separate yellow from red, or to distinguish a collection of greens and blues from white and black.

Ultimately, the language evolves to 11 basic color names: white, black, gray, red, orange, yellow, green, blue, violet/purple, pink, and brown. Some languages (namely Japanese, Russian, and Italian) have further broken the blue category into sky blue and navy blue.

Yes, I understand that my rendition of orange is not so good

Hang on, John. In English, we have sky blue and navy blue. Why aren't these considered basic color names? 

That's a fair question. In English, we distinguish between the two versions of blue by adding the modifiers sky and navy. But, we have a lot of other modifiers that could be applied to blue to arrive at the colors cadet blue, cobalt blue, greenish blue, midnight blue, Pacific blue, pale blue, purplish blue, robin's egg blue, steel blue, and turquoise blue. None of these are basic color names because they are just modifiers of the basic name blue. Chromolinguists also have a requirement that basic color names must also be monolexic, meaning they must be one word.

Getting back to the theory of Berlin and Kay, here is the original sequence, taken from a subsequent paper by one of the same authors [2]:

Original B&K evolutionary sequence of color term development

If this is all true, then it explains the use of red applied to Bermuda onions and also to cabbage which happens to have lots of anthocyanin, both of which are actually purple. At the time when it became necessary to distinguish between Spanish onions and Bermuda onions, the word purple was not commonly used in the language. In the diagram above, the language was in Stage VI. Red was the common term that signified either purple or red, so red was the name given.

The terms red onion and red cabbage stuck, in much the same way as the anachronistic phrases "hit return", "dial your phone number" and "tape a TV show".

Here are some more examples of vestigial chomo-misnomers: What color are your blue jeans?

[1] Berlin, B., Kay, P.: Basic Color Terms: Their Universality and Evolution. University of California Press, Berkeley/Los Angeles (1969)


[2] Kay, Paul, and Richard S. Cook, World Color Survey, Encyclopedia of Color Science and Technology, Springer Science+Business Media New York 2015