CMYK color model

Halftoning (or screening) allows a printer to produce continuous tones by varying the size and spacing of small ink dots. This creates the perception of intermediate colors between the primary inks. For example, 20% coverage of magenta ink produces a pink tone rather than full magenta. Without halftoning, CMYK inks would only produce eight colors: the three primaries (cyan, magenta, yellow), the three secondaries (red, green, blue), white, and black. == Comparison to CMY ==

CMYK is an extension of the CMY model, which omits black ink. Black ink is added in four-color printing for several practical reasons: • The "key" (K) plate provides outlines and text with higher precision than using three inks alone. • Using black ink reduces ink consumption and drying time, preventing paper distortion or tearing. • Combining 100% cyan, magenta, and yellow produces a dark but imperfect black; black ink produces more consistent dark tones. • Black ink is more cost-effective than combining three colored inks. A dark area printed with CMY and then overlaid with black is referred to as rich black. Techniques such as under color removal, under color addition, and gray component replacement determine the amount of black ink relative to other inks. == Other printer color models ==

CMYK contrasts with spot color printing, where specific inks produce fixed colors. Some presses can combine process and spot colors. High-quality printed materials often require full-color process printing, sometimes augmented with spot colors or metallic inks. Extended gamut systems (e.g., CMYKOG Hexachrome) increase the range of reproducible colors beyond standard CMYK. == Comparison with RGB displays ==

RGB displays emit light and produce additive colors, while CMYK inks absorb light and produce subtractive colors. Each model has a distinct color gamut; colors visible on one may not be reproducible on the other. Spectrum of printed paper The CMYK model codes for absorption of light. Cyan absorbs red, magenta absorbs green, and yellow absorbs blue. Black ideally absorbs all wavelengths. == Conversion ==

RGB and CMYK are device-dependent; no universal formula converts between them. Color management systems using ICC profiles are required to map between devices accurately. Conversion depends on device gamuts, rendering intents, and factors such as dot gain and Neugebauer primaries. Predefined printing standards, such as Specifications for Web Offset Publications, include ICC profiles for software and operating systems. File:NIEdot367.jpg|Early three-color process (1902) File:NIEdot367-modern.jpg|Approximation using CMY colors == See also ==