CMYK Colors Explained: How Print Color Really Works
Printers can't emit light — they lay translucent inks that absorb it. Cyan absorbs red, magenta absorbs green, yellow absorbs blue: stack them and you subtract your way to any color. That's CMYK, the subtractive model, with K (Key/black) added because real-world CMY inks mix to a muddy brown rather than true black — and because black ink is cheaper and sharper for text.
Screen to print: what changes
The CMYK gamut is smaller than sRGB, especially for saturated blues, greens and oranges. Electric blue #0000FF becomes a duller violet-blue on paper; neon anything is unprintable. Convert early with our RGB to CMYK or HEX to CMYK tools to preview the compromise, and get final proofs from your print shop — actual results depend on ink, paper and press profile (coated vs uncoated stock differ dramatically).
Black is complicated
| Black type | Values | Use |
|---|---|---|
| Plain black | 0/0/0/100 | Body text — sharp, no registration issues |
| Rich black | 60/40/40/100 | Large dark areas — deeper, denser |
| Registration black | 100/100/100/100 | Printer's marks only — never artwork |
Practical prep checklist
Work in your print profile (commonly ISO Coated / GRACoL), keep total ink coverage under ~300%, set text in plain K, convert critical brand colors deliberately rather than trusting auto-conversion, and see digital vs print colors for the full workflow.