Definition: To reproduce full-color photographic images, typical printing presses use 4 colors of ink. The four inks are placed on the paper in layers of dots that combine to create the illusion of many more colors. CMYK refers to the 4 ink colors used by the printing press. C is cyan (blue), M is magenta (red), Y is yellow, and K is black, the key plate or keyline color.
A mistake often made when submitting artwork for 4-color printing is not converting the images to the CMYK color space. This is needed so that the file can be separated into the four colors (see example) so that a separate printing plate can be made for each of the colors.
Also Known As: 4-color | process colors
Alternate Spellings: CYMK
Examples: The illustration on this page shows a color photograph (center) separated into its CMYK components. A separate plate for the printing press would be made from each one. Those areas on the C plate, for example, that are black and shades of gray would print in varying shades of Cyan. The white areas get no Cyan. Each ink is added in turn to create the final full color image on paper.
