Print Versus Screen Color
One surface emits light and the other reflects it. Everything that goes wrong between design and press follows from that single difference.
Short answer: a screen makes color by adding light, starting from black and switching emitters on. Paper makes color by removing light, starting from white and laying down inks that absorb parts of the spectrum. The screen is a light source; the print is a filter over someone else's light source. That means a print has no color of its own until you specify the illumination, its brightest possible white is the paper, and its gamut is smaller in most directions and not a subset in all of them. Getting a match is not a matter of converting numbers. It is a matter of deciding what "match" is going to mean.
Adding light versus taking it away
| Screen | ||
|---|---|---|
| Starting state | Black; nothing emitted | White; the substrate reflecting whatever light is present |
| Adding a colorant | Adds light, moves towards white | Absorbs light, moves towards black |
| Brightest white | All emitters at maximum | Bare paper, which is not the same white twice |
| Depends on the room | Somewhat; ambient light lifts the blacks | Entirely; with no light there is no image |
| Darkest black | Limited by panel leakage | Limited by how much ink the paper will take |
The row that catches people is the third one. On screen, white is a number you can reach. On paper, white is a physical object with a color of its own, and two stocks side by side will not agree. That is not an error to be corrected; it is the medium.
CMYK is not a color space
This is the single most useful correction to make. A CMYK value is not a color. It is a set of four ink coverage percentages, and what those percentages produce depends on which inks, in which order, on which substrate, with which screening, dried how, and viewed under what light.
The international standard for offset process control makes this explicit: the parameters it specifies include the ink set, the printing ink sequence, the substrate, the measured coordinates of the solid patches and their overprints, the screening and the tone value. Change any of those and the same four numbers give you a different color. A printing condition, not a set of numbers, is the thing that has a gamut.
The practical consequence is that "convert to CMYK" is an incomplete instruction. Convert to which printing condition is the real question, and the answer normally comes from the printer rather than from a menu default. The mechanism that carries that answer is a profile, described on color management and ICC profiles.
Where the two gamuts actually differ
The usual summary, that print has a smaller gamut, is true on average and misleading in detail. A screen reaches much further into saturated blues, greens and bright reds. A good offset condition on coated stock can reach some saturated cyans and yellows that sRGB cannot hold. The two gamuts overlap heavily and each pokes out of the other in places.
The reference point worth keeping in mind is Pointer's 1980 survey of real surface colors, derived from over four thousand samples. Real objects occupy a region that neither sRGB nor a typical print condition fully contains, which is a useful antidote to treating either one as the natural home of color.
Where the print side is unambiguously narrower is at the extremes of lightness. The paper sets the ceiling and the maximum ink load sets the floor, so the whole tonal range is compressed compared with a backlit screen, and it is compressed at both ends at once.
What compression does to your image
Because the destination range is smaller, something has to be discarded or squeezed, and the choice has a name: the rendering intent. Colorimetric intents keep in-gamut colors exact and clip the rest, which is right for a brand color and wrong for a photograph, because clipping turns the detail in a saturated area into a flat shape. Perceptual intent compresses everything so that relationships survive, which is right for a photograph and wrong for a brand color, because nothing stays exactly where it was.
The CIE published guidelines for evaluating gamut mapping algorithms precisely because vendors solve this differently and there was no agreed basis for comparing results. In practice this means two applications can both be behaving correctly and still give you different prints from the same file.
Soft proofing, and what it cannot do
Soft proofing simulates the print on the screen: the software converts through the print profile and back, so you see approximately what the compression will cost you. It is genuinely useful and it has hard limits.
It cannot make a backlit screen look like a reflective surface, and the mismatch is largest in the highlights, where the screen's white is far brighter than paper. It depends completely on the profile describing the real printing condition rather than a generic one. And it only means anything under controlled viewing, which is why standards for viewing conditions specify the spectrum of the light rather than only its color temperature. Research on camera-assisted soft proofing exists precisely because getting the two media to agree by eye is difficult enough to be a research problem.
The habit that helps most is to enable the paper-simulation option, which dims the screen white towards the substrate white. It looks wrong for about a minute and then it looks like the print, because your visual system adapts, which is the same color constancy machinery that makes judging a white point so hard.
A workflow that survives contact with a press
Design in a working space and convert late. Editing in a print space early throws away colors you might have kept.
Get the printing condition from the printer. Not from a default. This single step removes most surprises.
Choose the intent per element. Photographs perceptual, brand colors colorimetric. There is no single right answer for a page that contains both.
Do not judge a proof under office lighting. The whole comparison is only defined under specified viewing conditions.
Expect the deep saturated areas to change. They are the part that cannot survive, and knowing that in advance is better than discovering it on press.
The connection to the games
Gamut compression is an interval problem. Two colors that sat a comfortable distance apart on screen can arrive on paper much closer together, and a set of steps that read as even can arrive uneven, because the compression is not the same everywhere in the space.
Huespan is that judgement isolated: you are shown a color interval and asked to reproduce it elsewhere in the space. It is a good way to discover that your sense of "the same distance" is not constant across hues and lightness levels, which is exactly why gamut mapping is hard and why the same algorithm can look right in one image and wrong in another. The measurement side of the same question is on color difference and Delta-E.
Is your sense of distance constant? Huespan shows you a color interval and asks you to reproduce it. The places where you drift are the places gamut compression will surprise you.
Frequently asked questions
Why does my print never match my screen?
Because the two are different kinds of object. A screen emits light and a print filters whatever light is in the room, so the print has no colour of its own until you specify the illumination. Its brightest white is the paper and its tonal range is compressed at both ends. A match is something you define, not something you recover.
Is CMYK a colour space?
No, and this is the most useful correction to make. Four ink percentages describe coverage, not colour. What they produce depends on the ink set, the printing sequence, the substrate, the screening and the tone value. A printing condition has a gamut; a set of CMYK numbers on its own does not.
Should I convert my files to CMYK myself?
Only once you know which printing condition to convert to, which normally means asking the printer. Converting to a generic default is how work gets sent to press in the wrong condition. Design in a working space, convert late, and let a profile carry the printer's answer.
Is the print gamut simply smaller than sRGB?
Smaller on average, but not a subset. A screen reaches much further into saturated blues, greens and bright reds. A good offset condition on coated stock can reach some saturated cyans and yellows that sRGB cannot hold. The two overlap heavily and each pokes out of the other in places.
Which rendering intent should I pick for a page with photos and a logo?
Different intents for different elements. Photographs take perceptual, because compressing everything preserves the relationships inside the image. Brand colours take a colorimetric intent, because they need to land exactly where they were specified. A single intent for a mixed page is a compromise in one direction or the other.
What is soft proofing actually showing me?
A simulation on screen of what the print conversion will cost, produced by converting through the print profile and back. It is useful for seeing which saturated areas will flatten. It cannot make a backlit screen behave like paper, the highlights are where it diverges most, and it means nothing under uncontrolled lighting.
Why does the paper simulation option make everything look dull?
Because it is dimming the screen's white towards the actual substrate white, which is much darker than a backlit panel at full output. It looks wrong for a minute and then looks like the print, because your visual system adapts to the new white. That adaptation is the same effect that makes judging a monitor white point so difficult.
Why do two printers give different results from the same file?
Different printing conditions, and possibly different gamut mapping. Ink sets, substrates and screening all differ, and the algorithms that squeeze out-of-gamut colours into range are not standardised between vendors. Two applications can both behave correctly and still hand you different prints.
Keep reading
- Color management and ICC profiles: how a printing condition gets described.
- sRGB, Display P3 and wide gamut: the screen side of the same gamut question.
- Display calibration basics: why the white point choice matters when a print is in the room.
Sources: International Organization for Standardization, ISO 12647-2:2013, Graphic technology: process control for the production of half-tone colour separations, proof and production prints, Part 2: Offset lithographic processes; International Organization for Standardization, ISO 3664:2009, Graphic technology and photography: viewing conditions; International Commission on Illumination, CIE 156:2004, Guidelines for the evaluation of gamut mapping algorithms; Pointer, M. R. (1980), The gamut of real surface colours, Color Research & Application 5(3), 145; Lee, K.-Y., Park, R.-H. and Lee, S.-W. (2012), Colour matching for soft proofing using a camera, IET Image Processing 6(3), 292; Green, P. (ed.) (2010), Color Management: Understanding and Using ICC Profiles, Wiley; Poynton, C., Color FAQ; W3C, A Standard Default Color Space for the Internet: sRGB.
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