CMYK color model

The CMYK printing process was invented in the 1890s, when newspapers began to publish color comic strips.

[9] Comparisons between RGB displays and CMYK prints can be difficult, since the color reproduction technologies and properties are very different.

A computer monitor mixes shades of red, green, and blue light to create color images.

A CMYK printer instead uses light-absorbing cyan, magenta, and yellow inks, whose colors are mixed using dithering, halftoning, or some other optical technique.

The precision of the conversion depends on the profile itself, the exact methodology, and because the gamuts do not generally match, the rendering intent and constraints such as ink limit.

ICC profiles, internally built out of lookup tables and other transformation functions, are capable of handling many effects of ink blending.

The problem of computing a colorimetric estimate of the color that results from printing various combinations of ink has been addressed by many scientists.

The resultant color would be an area-weighted colorimetric combination of these primary colors, except that the Yule–Nielsen effect of scattered light between and within the areas complicates the physics and the analysis; empirical formulas for such analysis have been developed, in terms of detailed dye combination absorption spectra and empirical parameters.

One of them is the US Specifications for Web Offset Publications, which has its ICC color profile built into some software including Microsoft Office (as Agfa RSWOP.icm).

This diagram shows three examples of color halftoning with CMYK separations, as well as the combined halftone pattern and how the human eye would observe the combined halftone pattern from a sufficient distance.
A color photograph of the Teton Range
Inspection CMYK colors of offset printing on a paper
Comparison of some RGB and CMYK color gamuts on a CIE 1931 xy chromaticity diagram
Spectrum of the visible wavelengths on printed paper (SCA Graphosilk). Shown is the transition from red to yellow. White, red, blue, and green are shown for reference. Readings from a white orchid flower, a rose (red and yellow petals), and a red cyclamen flower are shown for comparison. The units of spectral power are simply raw sensor values (with a linear response at specific wavelengths).
Early representation of the three-color process (1902)
Approximation of the image using CMY colors.