Subtractive color model

Print and paint create color with pigments that absorb light. This is the subtractive model: each ink subtracts some of the light that would otherwise reflect back to your eyes.

The more inks you mix, the less light reflects, so the mix gets darker. Where cyan, magenta and yellow all overlap, you get a dark, near-black color.

Printers add black, called key, to cyan, magenta and yellow (CMYK), because black ink gives deeper blacks and sharper text. In art class, painters traditionally learn red, yellow and blue as primaries.