CMYK vs RGB: why screen colors look different on paper

Your screen builds color out of light: red, green and blue (RGB). A printing press builds it out of ink on paper: cyan, magenta, yellow and black (CMYK). The two systems can't reproduce the same set of colors, and some of the bright colors you see on a monitor simply don't exist in ink. You can't make that gap disappear, but you can keep it under control once you know where it comes from.

Light vs ink

On a screen you start from black, a pixel that's switched off, and add light. Red, green and blue at full strength make white. That's additive color: you build it by combining light sources, the same way monitors, cameras and scanners work.

Paper works the other way around. You start from white, and every layer of ink absorbs part of the light and reflects the rest. That's subtractive color, the same principle as paint and dyes. The more ink you lay down, the darker the color gets.

Each system has its own range of colors it can reproduce, called its gamut. Printing Industries of America shows in a color diagram how a standard CMYK print gamut is smaller than the sRGB or Adobe RGB gamut of a screen. Anything outside the print gamut gets moved to the closest printable color when the file is converted.

In practice, the colors that suffer most are the very saturated ones: an electric blue, a bright green, a fluorescent orange. On paper they come out duller, no matter how good the printer is, because the ink can't reach them.

Your screen is not the reference

There's a second problem: screens don't agree with each other either. HP and Microsoft proposed sRGB in 1996 as a default color space for the internet and operating systems, based on how typical monitors of the day behaved. It's a shared reference, but your phone, your coworker's laptop and the monitor in our studio still display color differently, especially with brightness turned all the way up.

So when you approve a color on your phone, you're approving a color on your phone. For brand colors it's safer to look at a printed proof or a swatch book.

Paper changes the result

The same CMYK file doesn't print the same on every stock. That's why there are different color profiles for different printing conditions. The European Color Initiative (ECI), for example, publishes:

On uncoated paper the ink soaks into the fibers, so colors come out warmer and less vivid. Lamination shifts them a little too. If you pick the paper after approving colors on screen, you may end up with a different color than you expected. Our business cards page shows the options we offer.

What to do before printing

1. Ask the printer which profile they use. Convert from RGB to CMYK with the profile for the actual print condition, not whatever your software has set by default.
2. Keep your originals in RGB. Leave photos and illustrations in their original files. Convert once, at the end, so you don't lose color with every save.
3. Use soft proofing. Design software can simulate on screen how a file will look with a given profile. It's not a real proof, but it shows you early which colors will go flat.
4. Define brand colors in CMYK too. A HEX code works for your website. For print you also need CMYK values, checked on the paper you usually print on.
5. Use a spot color when it has to match exactly. Besides CMYK, printing can use special, metallic or Pantone inks mixed separately. It's worth it for a logo that goes on hundreds of products.
6. Ask for a proof on large runs. One printed sheet on the chosen paper tells you more than any screen.

What to send us

If we're preparing the files, it helps to know up front where the job is going: coated or uncoated paper, laminated or not, offset or digital. If you already have brand colors, send everything you've got: HEX, CMYK, Pantone, or at least a printed piece you liked. For stickers, labels and other small items, our stickers page shows what we make.