Talk:CMYK color model/Archive 2

Archive 1Archive 2

Origination of the last letter in the CMYK abbreviation

Answering why the abbreviation originates from "cyan, magenta, yellow, black".
When the subtractive CMY approach had been decided on as one best fitting white-paper printing purposes (it would be RGB if most of paper were black) and the problems of ink mixing and ink economy had arise, the only accompanying color could be and was chosen is the black color for the reason that it is the only antipode to the white color and this way is the best color of contrast for a white sheet of paper. Next, the abbreviation CMYB was assembled (still being encountered), but seeing that "B" may be confused as standing for "blue", like it was for the existing RGB color model, the last letter "K", color-unoccupied at the time, was picked to represent the color.
Those folks who have any doubts can google the text cmyk "cyan, magenta, yellow" [1] and for several result pages compare by themselves how much predominantly this color sequence ends with "black" making out something like "CMYK stands for cyan, magenta, yellow, and black.". So almost everywhere, including this Wiki article, when it is placed "K", it is meant black and only black.
In addition, here are some quotes and references:
"Short for Cyan-Magenta-Yellow-Black" [2]
"CMYK - Cyan, Magenta, Yellow, blacK" [3]
"The C stands for cyan (aqua), M stands for magenta (pink), Y is yellow, and K stands for black." [4]
"CMYK is an abbreviation for Cyan, Magenta, Yellow, and blacK; the primary colors of a printer's pallette." [5]
--SunnySideOfStreet (t) 20 November 2007

Do you have any more credible sources? Perhaps some book about printing processes, instead of entries in random online glossaries? --jacobolus (t) 13:44, 20 November 2007 (UTC)
That "k" stands for "key" is pretty well established (see, for example [6], [7], [8], [9], [10], [11], [12], [13], [14], [15], etc. Here's what Yahoo Answers has to say. Note that indeed, "key" and "black" are basically interchangeable, and calling this the "cyan, magenta, yellow, black" color model is perfectly legitimate. That doesn't mean that "k" stands for black though.) --jacobolus (t) 13:50, 20 November 2007 (UTC)
Thanks to your first Adobe-related book examples, Jacobolus, I finally have remembered where I read the "story": it's from Adobe Photoshop Help — I'm sure a very reliable source hardly can be rejected. So, Adobe Photoshop CS Help says (a paragraph): "In theory, pure cyan (C), magenta (M), and yellow (Y) pigments should combine to absorb all light and produce black. Because all printing inks contain some impurities, however, these three inks actually produce a muddy brown. For this reason, black ink (K) is used in addition to the cyan, magenta, and yellow inks in four-color printing. (K is used for black instead of B to avoid confusion with blue.)" [http://www.pdesigner.net/photoshopcs/1_6_2_4.html] End of the quote (the bold is mine). Does anyone see a "key" in it?
Now about books. I still think that Google's statistics [16] is really noteworthy, but if you like books, then Ok, here are the book examples: [17], [18], [19], [20], [21], [22], [23], [24], [25], [26], [27], [28], [29], [30], [31], and so on. But I wouldn't want the discussion to come at "who is to give more examples", so the next I hope will end the book theme. Here are the comparison of "key"-vs-"black" results from Google Book Search ("All books" mode):
phrase cmyk cyan magenta yellow key
books found: 275
phrase cmyk cyan magenta yellow black
books found: 660
660 of "black" against 275 of "key". But you may rebuke that "black" is just more frequently encountered word than "key" as regards the subject of CMYK color model, and where is "black", there may be "key" as well. So here comes the final experiment on Google Book Search. Concerning CMYK, let's find cyan magenta yellow black combination but without key:
phrase cmyk cyan magenta yellow black -key
books found: 650
I will do my edition for the last time and leave the discussion, but before you, Jacobolus, decide to redo yours, wait for and pay attention to somebodies' extra opinions. --SunnySideOfStreet (t) 20 November 2007
You completely miss the point. CMYK does indeed imply "cyan, yellow, magenta, and black", but the letter "k" is used because black was the "key" plate, not because black has a "k" in it. This is not a matter of opinion, but is simply a well-documented part of the history of printing. --jacobolus (t) 17:18, 20 November 2007 (UTC)
the "Key" plate was used to change the language on the books... images remained the same but the text changed with languages.... soooo a "key" plate was made... this process had actually five plates "CMYK" for printing the images (Black is needed in the images).... and the "Key" plate to print the texts in different languages and to separate text from images. --Reuben von Insel —Preceding unsigned comment added by 189.163.196.120 (talk) 07:30, 26 February 2008 (UTC)
Just because "black" has a "k" in it. See carefully [32], [33], [34], [35], [36], [37], [38], [39], [40], [41], [42], [43], [44], [45], [46]. --SunnySideOfStreet (t) 20 November 2007
The "K" comes to differenciate it from the "B" (Blue), before computers you needed seven fimls the R(Red), the G (Green) the B (Blue) and then from those you made another three C (Cyan) M (Magenta) and Y (Yellow), then you took a picture of the original with the text and came up with the Black... but then you would have RGBCMY"B"... and to avoid confusions the black was labeled "K". then you used the CMYK films to "burn" (with uv-light) the plates that were later used in the offset press. to print color with good quality you need four plates.

- - ::::There was sometimes another plate called the "Key" plate and was used to make quick changes on the press. You would print 100,000 brochures with the same pictures, and then change the "Key Plates" to print 10,000 for German customers and another 90,000 for the american market. Printing used to be very expensive and using a "Key" plate to change text was more cost effective... to make it short. There was a "Key" plate... but it it wasn't the "K" plate... That's a common misconception with graphic designers that don't really know what's going on on the printing business --Ruben von Insel —Preceding unsigned comment added by 189.163.196.120 (talk) 07:42, 26 February 2008 (UTC)


Of the books you just linked to, 3 suggest that the "k" comes from the term "key plate", 2 suggest that it comes from the last letter of "black" (specifically, the first and sixth links, Digital Imaging: Essential Skills and Computer Graphics: Theory Into Practice), and the rest fail to mention the derivation of the "K" in CMYK at all. I'm not sure I find these two sources credible, however; both are quite simplistic, and are mainly about digital imaging, only briefly discussing CMYK. For those unfamiliar with printing, "k" as the last letter of "black" is a reasonable assumption for the derivation of the name. I place more trust in Handbook of Print Media: Technologies and Production Methods (your second-to-last link), which explains various printing processes in great detail, and explains quite clearly on page 82 that "It is known that in subtractive color mixing the color "black" (letter symbol "K" for "Key Color") is produced by the superimposition or the overprinting of the colors red (R), green (G), blue (B) or cyan (C), magenta (M), yellow (Y). PostScript's architects had assumed that a combination of the same proportions of the three primary colors would produce an ideal neutral gray and that consequently the largest possible proportion of black in the color separation could be calculated from the largest common proportion of primary colors. These assumptions were so far removed from actual practice that during activation of the first generation of PostScript color printing systems unsatisfactory color print results appeared. This was rectified in later versions." Which (along with the following couple of pages) would be a great source for the expansion of this article. --jacobolus (t) 17:50, 20 November 2007 (UTC)
So, for those keeping score at home, we've got at least 15-20 sources, including some hard core printing books, claiming that "k" comes from "key plate" or "key color", against a few web glossaries no one has ever heard of, and a couple of digital imaging books, claiming that it is from the last letter of "black". I'd like to get a definitive source saying something like "it is a common misconception that 'k' comes from the last letter in 'black'", but I doubt such a source is going to turn up. If you want though, we can maybe add a footnote about it to the article, as you seem adamant that the "k" from "black" theory be represented. --jacobolus (t) 17:57, 20 November 2007 (UTC)
Hah! Ask and ye shall receive: Getting it Right in Print: Digital Pre-press for Graphic Designers: "It is a common misconception that black is assigned the letter 'K' because if it was called 'B' it could be confused with blue. While plausible, this is not the case". --jacobolus (t) 18:01, 20 November 2007 (UTC)
The first three book examples say that "k" originates from "black" explicitly: Digital Imaging: Essential Skills, Artist's Color Manual: The Complete Guide to Working with Color, and Video Demystified: A Handbook for the Digital Engineer, and also the sixth Computer Graphics: Theory Into Practice and the eighth one Rapidex DTP Course (DTP is Desktop Publishing). The remaining books decode CMYK without use of "key" (at all) but placing "and black" after "cyan, magenta, yellow". It's an opinion of the author of a book, yours or mine (you can write a book, I can do it as well). But it's not a matter of source/book reliability -- it's a matter of statistics of the most prevalent interpretation. See with consideration the Google examinations I had done. I cannot waste my time for this no more.
--SunnySideOfStreet (t) 20 November 2007
I'm sorry, but the statement that "CMYK stands for cyan, magenta, yellow, black" is completely correct, and does not indicate anything about the derivation of the "K", one way or the other. You are right however that your second link, which seems to be mostly directed at painters, with a brief explanation of process color, used partly as a lead-in to explain why pointillism works, also claims that "K" comes from the last letter for black. I really don't think this source is as credible as the several technical printing books which claim otherwise, but you're right: You tracked down 4 books which claim that "k" comes from the last letter. --jacobolus (t) 18:42, 20 November 2007 (UTC)
Here's a source from 1872 (entitled Photo-engraving: A Practical Treatise on the Production of Printing Blocks by Modern Photographic Methods) which states: "For color work the design of the black or key plate is generally transferred to the surface of the zinc…", and one from 1910 (Colour Printing and Colour Printers) which says: "…only a few prints seem to have been produced in Paris by Le Blon himself, who died in … 1741. … His own work, at any rate in the earlier years, seems to have been strictly on the three-colour basis, but there has been a good deal of controversy as to whether or not he used a fourth or black plate as a key for the colours." And here's a 1903 source about Le Blon (American Architect and Building News): "He engraved a separate plate to carry each color, and used red, yellow and blue, with sometimes a key-plate in neutral tone." (Of course these sources are all from a time before one-letter abbreviations seem to have been used for any of the plates. That is, the abbreviation “CMYK” wasn't invented until later). --jacobolus (t) 19:32, 20 November 2007 (UTC)
SunnySide, the big difference between your sources and Jacobolus' sources is his are much older some going as far back 1800's. Which in the case of the original meaning of a word or acronym is more valid than the a newer source. Wikipedia is not about finding out what most people think about a particular issue which is what you have done, but instead finding out the truth of the matter regardless if it is well known or not. 68.50.168.239 (talk) 00:53, 22 November 2007 (UTC)

I just found out that some people believe the K stands for Kelvin. Now my head hurts.--87.162.12.35 (talk) 01:29, 10 February 2010 (UTC)

During the evolution of the lithographic process, proofing processes were derived based on architechtural blueprints and that photo-chemical process leading to what printers know as bluelines or dylux papers, which allowed printers to proof works before committing to press. Often customers would see these proofs in prussian blue (cyanotype) and would request to have the final work printed in that stunning color as apposed to the ever popular black. The process of photo-chemical copying was known as reflex printing a centurey later Pantone created a blue base ink that was similar in color to the photo-chemical process and called it reflex blue which emulated the blue hue of the blueline prints, Blue was a well established color such as black before the 4 color process, the original phtographic color separation required for the 4 color process was simply CMY when black was added to the process (and oly after it was photographically separated) the process was known as CMYB (for the addition of black) but changed to K so there was absolutely no confussion over the ever popular Blue. In the printing process black is the last color to print so black text and fine details are above the other colors - it is not used to register the other plates such as misrepresented by being a 'key' registration plate. —Preceding unsigned comment added by 71.116.44.122 (talk) 00:10, 10 June 2010 (UTC)


I have always believed the K stands for 'Kohl' a black substance dating back to ancient times, however I have no recollection of where I picked that up

need for a history section

All this discussion of the origin of the "K" in CMYK has me realizing that this article (and the color printing article as well), desperately need some expert attention, including adding lots of sources, and creation of history sections. This 1896 article “How to Study Process Chromatics” on pages 202-205, 248-250, 322-324, 393-395, and 436-439 of Wilson's Photographic Magazine, seems like a pretty decent source on the printing process of that time. --jacobolus (t) 19:44, 20 November 2007 (UTC)

Hear hear. Even if 'K' has a legacy independent of 'Black', why should the article state that it is 'wrong' to consider K as the last letter of Black. Dozens of printed sources say that 'K' is Black because 'B' implies blue, without mentioning key at all. It would not be the first time that a idiomatic rather than historic choice would be preferred for its mnemonic value. (For example 'the three Rs' or Celsius instead of Centigrade). Aapparently a 'key plate' is something distinct (though often the same) as the black. The article should explain this point. Put it this way: Is the 'K' channel ever used for anything but black? A historical perspective would allow both explanations to stand in the proper context without either needing to be 'wrong'.Brennanyoung (talk) 11:43, 18 January 2011 (UTC)

CMYK vs YMCK

I have sometimes encountered colours in the following format "PP YMCK" where PP is a simple profile and the other values are the colours in steps of 10 percentage points (with X representing 100%). For example: "ec X210" reads out 100% Yellow, 20% Magenta, 10% Cyan, 0% Key when printed on Euro Coated. Is this an obsolete syntax? moliate (talk) 20:40, 31 May 2011 (UTC)

Do you have a source for that? Just personal experience isn’t verifiable by other editors. –jacobolus (t) 03:32, 3 June 2011 (UTC)
I have mainly seen it in older printed material (mostly german, danish and swedish). I have been searching for it's origin since I made the query, but found little of interest. I would guess it is obsolete, likely regional, and of little interest for the article. If anyone is interested; here is a webpage from the National Archives of Sweden where it's still used [47]. It's in swedish, though: gult=yellow, svart=black. moliate (talk) 18:46, 3 June 2011 (UTC)

Wrong denominator

Why use 255, the wrong denominator, instead of 256, obviously the right one? A computer will divide by 256 using bit-shifting, which is simple, fast, and accurate; dividing by 255 is not only inaccurate mathematically, but introduces a heck of a lot of machine cycles. Unfree (talk) 16:22, 14 September 2009 (UTC)

If we use 0 to represent 0, and 255 to represent 1, as approximations to real numbers, then the range is 255. I’m not sure how you decided that 256 is obviously right, but that is not correct. –jacobolus (t) 21:24, 24 June 2010 (UTC)
A byte (octet) is the usual unit of digital storage and can represent the integers 0 to 255 but not 256. Simple bit shifting is not enough to divide accurately by 256 because the least significant bit needs special treatment if you hope for accuracy. Cuddlyable3 (talk) 19:37, 24 September 2011 (UTC)

animation of CMYK space

 
A visualization of CMYK color space

I removed this image from the article, because I don’t think it is helpful, for the following reasons:

  1. It does not accurately show the colors C, M, Y of the CMYK model, making it highly misleading to readers.
  2. The way the spinning animation works out, it is very difficult to distinguish individual color blots in the interior of the space, with the result that a viewer doesn’t really get an idea how the geometry works out, and speaking only for myself I find the effect quite distracting.
  3. CMYK isn’t very well represented as a cube anyway, because (a) there are four inks being used, not three, and (b) the result of mixing spots of ink of different sizes is complicated and non-linear.

Better might be to show some CMYK gamuts in CIELAB (or similar) space, or to try to explain in diagrams some of the models used for conversion into CMYK, gamut mapping, etc. I’m not sure, but some kind of useful geometric diagrams might be devised. Better still would be some diagrams showing the spectral reflectance distributions of C, M, Y, K, and various combinations thereof. However, a picture just showing a cube with dimensions labeled CMYK is misleading and unelpful in my opinion. In other words, a diagram used in this article should give insight into how process printing actually works. –jacobolus (t) 22:08, 24 September 2011 (UTC)

The focus of the animation is the CMYK model, which is a mathematical abstraction, and not the device dependency of any particular print process. I consider it helpful in the same way as the animations at the articles RGB color space and YCbCr are in explaining a 3-D volume that can be difficult to visualize from a static drawing.
  1. We cannot show subtractive ink colors accurately but that does not mean the article cannot have diagrams. The colors I used are the same as here and here i.e. 125 colors uniformly filling the displayable range and mapped to the CMK space. Note: this is not perfect, there is no gamma correction and linearity is assumed. If anyone likes to propose a different colour law in terms of 24-bit RGB shades, I can see about putting them in the animation.
  2. Just noticing that it is a spinning object tells the viewer it is something in 3-D. It helps to notice that the cube rotates about its diagonal which is the K axis. Then one understands the geometry.
  3. The goal is to give a qualitative visualization of how ink densities are coordinated like dimensions of a space. a) In principle three inks can define the whole gamut which is therefore a cube. The article explains that black ink is added to "save money on ink" and to address the inadequacy of affordable CMK inks in very dark tones.
I think it is a forlorn expectation that any Wikipedia diagram can provide colorimetrically accurate color swatches. It is correct to show that the CMK trio of subtractive inks work, to a good first approximation, as orthogonal variables that define a color space.
jacobolus has ideas for further geometric diagrams of the printing process that should be helpful if they are based on reliable sources. May we hear more? Cuddlyable3 (talk) 00:21, 25 September 2011 (UTC)
Inre your #1, the problem is that this diagram doesn’t even attempt to show CMYK colors. Flipping an RGB cube upside-down is an entirely misleading representation of CMY inks and their mixing, so misleading as to do more harm than any good that comes of putting across that CMYK can be thought of as three-dimensional in some ways. Inre your #2, there are much better ways of explaining that the model is three-dimensional than showing an incorrect diagram; also, “K axis” is not meaningful, and rotating the picture around one axis or another doesn’t really reveal anything significant. Inre your #3, I don’t understand what it means to “coordinate ink densities like dimensions of a space.”
Black ink is added for several reasons: (1) C, M, and Y inks never mix to a perfect black, (1a) the more relaxed the constraint is on C + Y + M looking black, the more room there is to improve other properties of those inks, including colorfastness, price, gamut size, etc, (2) Having too much ink on the page creates technical problems for the process: it’s harder to mix precisely, it dries more slowly, and so forth, (3) Reducing the amount of ink saves lots of money, (4) Purely black content such as text looks awful when printed using 3 colors instead of one, because it takes three times as much ink, isn’t ever registered exactly perfectly and so is fuzzy around the edges, doesn’t actually look neutral black, etc.
I don’t know what a “forlorn expectation” would be. If you want to show a three dimensional diagram of mixtures of various densities of C, M, and Y inks, that’s probably fine. My recommendations in that case would be (A) fix the other problems with this diagram (the unreadable axes, the dizzying effect of the spinning dots, the arbitrary orientation), and (B) derive colors from some actual CMYK printer, or for example from a standard like GRACoL. –jacobolus (t) 07:28, 25 September 2011 (UTC)
  1. I agree, and here arises the forlorn expectation: we cannot display anything except displayable colors so let's not expect that. CMY (witholding K for the moment) is factually a 3-dimensional model. Increasing the quantity of a single ink subtracts more light of the wavelengths that it absorbs, and that variation is orthogonal to (independent of) the densities of the other two inks. This is the mathematical view and is not misleading. It does not include the non-linearity of ink combination, which of course should also be treated in the article.
  2. For visualizing a space-filling entity a picture is worth a thousand words, not least for the inexperienced reader. Flat drawings of 3-D objects in perspective are not universally recognizable and here we have the additional challenge of seeing through a filled volume. Please propose any better way. The article on Volume rendering will help.
  3. coordinated adj. Organized, working together. I relate this to the mathematical or cartographic meaning of coordinate n. A number representing the position of a point along a line
You give reasons 1 to 4 for adding black ink all of which I agree should be in the article. The animation could omit black and I did look at that. However it makes a convenient arbitrary rotation axis which in my view stabilises the perception of the animation. It would also be misleading to show the colour space filled right to the black vertex without the help of black ink.
Since we are approaching this from mathematic/graphic and practical printing viewpoints respectively I wish to explore your recommendations for a new diagram. I guess you think of something like this and I shall be happy to look over any sketches which you may show here or send me by e-mail. Cuddlyable3 (talk) 11:43, 25 September 2011 (UTC)
The point is, there is no “black vertex” that fits in a straight-forward cube. As you say, you can represent densities of C, M, Y inks with reference to a cube. You can’t just pick a spot on that cube and label it K though without being entirely misleading. If you want to make a cube, my recommendations again would be: for color choices pick something like GRACoL or SWOP and convert the vertex points (various combinations of C, M, Y) to sRGB (I'd recommend clipping out-of-gamut points along the chroma dimension of CIECAM02, but some other gamut mapping algorithm would also likely work, or you could use a CMM like Adobe's or Apple's); for the design, show something with a bit more obvious structure than a bunch of edgeless dots moving about. There's no ideal way to show a three-dimensional picture in two dimensions, but your current diagram makes it difficult to see any structure, because the visual effect of the spinning dots is highly distracting/dizzying, and a static picture showing surfaces of slices through the cube is dramatically clearer. Unfortunately Wikipedia isn’t capable of displaying interactive graphics; those work better still. –jacobolus (t) 23:10, 25 September 2011 (UTC)

Strictly speaking, that animation shows the CMY color space. It seems a reasonable representation to me. The addition of the K in CMYK is rather odd in that it does not add a fourth dimension to the colors available, but instead corrects some practical issues with mixing three inks together. So one could call this the CMYK modal as well, if that were explained. Algr (talk) 15:49, 27 October 2011 (UTC)

CIE1931 chromaticity diagram?

It would be nice if this article featured a CIE1931xy chromaticity diagram, such as the ones in ProPhoto RGB color space and Adobe RGB color space suitable for comparison with them. I realize not all CMYK color spaces are so precisely defined, but it would be helpful to have a rough guide for comparing RGB different RGB color spaces to CMYK spaces. jhawkinson (talk) 04:48, 8 January 2012 (UTC)

Unlike for "additive" light mixtures (where the primary colors have well-defined chromaticity which remains constant at varying intensity), subtractive pigment mixture models don’t lend themselves to representation on a 2-dimensional chromaticity diagram. That said, it would be nice to have some kind of graphic showing gamut comparisons. –jacobolus (t) 06:22, 9 January 2012 (UTC)

How to pronounce this Kmuc?

Ha? Thx! —Preceding unsigned comment added by 77.122.114.34 (talk) 14:48, 19 November 2007 (UTC)

Nobody? Well I say /smik/, but some disagree. Maybe Russians say /smuk/?--87.162.12.35 (talk) 01:20, 10 February 2010 (UTC)
I think most people spell it: C-M-Y-K62.131.126.171 (talk) 07:25, 7 September 2010 (UTC)
Yes, but if you *had* to pronounce it as a single syllable, instead of spelling it out, I would argue for a soft 'C' (i.e. an 'S') because the combination 'Km-' is a bit of a mouthful. In many languages, a 'Y' is pronounced more like a 'U' or (more specifically) 'Ü'. Native English speakers could try and say 'ee' as in 'cheek' with their cheeks and 'oo' (as if to whistle) with their lips to create the most correct vowel sound, but "smook" would not be misunderstood by most relevant audiences. Brennanyoung (talk) 10:35, 18 January 2011 (UTC)
I’ve never heard of anyone trying to pronounce CMYK as a single syllable, so I don’t think it’s relevant. –jacobolus (t) 15:02, 18 January 2011 (UTC)
No, indeed. I've always heard C-M-Y-K (see-em-why-ké) Rchard2scout (talk) 19:32, 5 September 2011 (UTC) (p.s. I am 62.131.126.171)

FWIW my local printer (SE England) used to call it "Sigh-muck" and I adopted this assuming it to be standard pronunciation. Other printers since have tended to reply by spelling it out "Oh, See-Em-Why-Kay" so I gradually realized that Sigh-muck is not ubiquitous. But checking online today I found that several people apparently pronounce it as "smike" (e.g. a US speaker on Forvo and other Google hits), others (Wikipedia-based?) say "C-Mike, Smick, Cymkey (Simky)" and Pronounce How incredibly says "kmeek". Perhaps this is the acronym with the greatest number of differing pronunciations? It sort of puts the GIF/JIF debate into the shade. Ozaru (talk) 16:35, 26 September 2013 (UTC)

Requested move

The following discussion is an archived discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. Editors desiring to contest the closing decision should consider a move review. No further edits should be made to this section.

The result of the move request was: not moved Armbrust The Homunculus 08:48, 15 October 2013 (UTC)


CMYK color modelCMYK – This article is the primary topic for "CMYK", which already redirects here. There is only one other topic, CMYK (EP), which is disambiguated by a hatnote. Per WP:PRECISION: "titles should be precise enough to unambiguously define the topical scope of the article, but no more precise than that." The redirect to "CMYK color model" is unnecessarily over-precise. Relisted. BDD (talk) 23:08, 8 October 2013 (UTC) sroc 💬 14:14, 27 September 2013 (UTC)

The above discussion is preserved as an archive of a requested move. Please do not modify it. Subsequent comments should be made in a new section on this talk page or in a move review. No further edits should be made to this section.

Diagram for gamut

 
Comparison of some RGB and CMYK colour gamuts on a CIE 1931 xy chromaticity diagram

This article could use a diagram showing a typical gamut, like sRGB has. -- Beland (talk) 19:23, 7 April 2014 (UTC)

  Done as on the right. cmɢʟeeτaʟκ 20:51, 13 April 2014 (UTC)

Pronounciation

What is the usual way to pronounce CMYK? I always thought it had to be "see-em-why-kay", but today I heard "smick". --194.166.244.119 (talk) 19:57, 27 October 2016 (UTC)

Keyline?

Under the heading, "Benefits of using black ink" we have: "In traditional preparation of color separations, a red keyline on the black line art marked the outline of solid or tint color areas. In some cases a black keyline was used when it served as both a color indicator and an outline to be printed in black. Because usually the black plate contained the keyline, the K in CMYK represents the keyline or black plate, also sometimes called the key plate."

I found this quite confusing. I'm having trouble finding out what keyline means in this context. At the top of the article we have: "The "K" in CMYK stands for key because in four-color printing, cyan, magenta, and yellow printing plates are carefully keyed, or aligned, with the key of the black key plate. Some sources suggest that the "K" in CMYK comes from the last letter in "black" and was chosen because B already means blue.[1][2] The CMYK model works by partially or entirely masking colors on a lighter, usually white, background. The ink reduces the light that would otherwise be reflected. Such a model is called subtractive because inks "subtract" brightness from white."

This directly states that the "K" stands for for either "key" as in "key plate" or that the "K" stands for the last letter of the word "black". There is no mention of keyline. What is keyline? Could we replace references to "keyline" with "key" if they are the same thing?

Thank you for reading. 80.7.27.189 (talk) 15:32, 7 November 2013 (UTC)

Black is the “key” ink, on the “key” plate. “K” stands for “key” (the thing about standing for the last letter in “black” is from later sources looking to retroactively justify the acronym). The “keyline” would be the physical line on the page, used to align the other plates “Key” and “keyline” aren’t the same thing. –jacobolus (t) 01:13, 12 November 2013 (UTC)
Oh, here. See keyline. –jacobolus (t) 01:42, 12 November 2013 (UTC)
Is there any reference of "k" standing for "key" instead of "blacK" before 2004? I cannot find any.147.156.233.217 (talk) 13:25, 30 May 2016 (UTC)
While neither are reliable sources, I know I've been calling that that since at least the early 90s, and also this article itself used the term in 2002, at its creation. Rwessel (talk) 18:49, 30 May 2016 (UTC)
I was always under the impression that K came from Kohl_(cosmetics) 80.169.39.58 (talk) 15:09, 9 January 2018 (UTC)

Pronunciation

Add please pronunciation information. Thanks. --DAVRONOVA.A. 12:37, 14 July 2018 (UTC)

History...?

What's the history of CMYK?

When/where was it first used?

Who developed it? — Preceding unsigned comment added by 61.93.233.246 (talk) 08:21, 4 October 2018 (UTC)

Requested move 5 February 2019

The following is a closed discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. Editors desiring to contest the closing decision should consider a move review after discussing it on the closer's talk page. No further edits should be made to this section.

The result of the move request was: Not moved. (non-admin closure)  samee  converse  10:38, 12 February 2019 (UTC)



CMYK color modelCMY color model – It would be great if we make it a perfect counterpart of the RGB color model. It contains both CMY color model and CMYK inks so I can't create another article named "CMY color model" because it will become a redirect to this article "CMYK color model. CMY color model itself isn't just about inks and having K as black for printers isn't necessary since it is already stated in the subtractive color that CMY will create black. I think we should change this article because RGB (it's counterpart color model in additive color or light) talks about not only of being a color model of modern devices but also the technicalities of it. This article focusing too much on CMYK inks in printing, not on the concept of the CMY color model itself. In this case, the CMYK inks in printing should be in a subheading then. I know this article is about the CMYK inks in printing but I think it would be better if this focuses on the general topic and the principles of CMY and I will volunteer to modify this article to focus in their color model. Jaspergeli (talk) 09:00, 5 February 2019 (UTC)

All the online references refer specifically to black, although actually the Teach Yourself Adobe Photoshop one is about the CcMmYK color model. 94.21.238.64 (talk) 09:43, 5 February 2019 (UTC)
Thank you for this, If you really wish me to, then I will do it! In this case, I will write about the concept of the CMY color model itself and how it works, not about the CMYK inks. Thank you so much. Jaspergeli (talk) 19:37, 8 February 2019 (UTC)

The above discussion is preserved as an archive of a requested move. Please do not modify it. Subsequent comments should be made in a new section on this talk page or in a move review. No further edits should be made to this section.