**CMYK** — cyan, magenta, yellow and key (black) — is the four-colour process used in print reproduction and one of the standard ways of specifying flag colours for printed materials. A CMYK value defines the percentages of each ink layer required to reproduce a given tincture, and is often supplied alongside Pantone references in an official flag specification. CMYK is device-dependent and can shift with paper, ink and press.
**Example**: A flag’s blue may be specified as Pantone 280C and, equivalently for print, as C100 M85 Y5 K20.
**See also**: [pantone](/glossary/pantone/), [rgb](/glossary/rgb/), [hex](/glossary/hex/), [construction-sheet](/glossary/construction-sheet/)