CMYKjärjestelmästä

The CMYK color model, also known as subtractive color, is a color model in which a range of colors can be reproduced by mixing specific proportions of cyan, magenta, yellow, and black ink. These four inks are known as the process inks. CMYK is used in color printing and in any application where color is represented by ink on a substrate, such as paper.

Cyan, magenta, and yellow are considered primary colors in this subtractive model because, when combined in varying degrees, they can theoretically produce a wide spectrum of colors. For example, mixing cyan and yellow produces green, magenta and yellow produce red, and cyan and magenta produce blue. In practice, however, mixing these three primaries does not produce a pure black; instead, it results in a dark, muddy brown.

To achieve true black and to deepen the shadows and contrast in an image, black ink (K, for key) is added. The use of black ink also reduces the amount of cyan, magenta, and yellow ink needed, which can save on ink costs and help the paper dry faster. The "K" designation for black originates from the idea that black ink was the "key" color plate in traditional four-color printing, providing the detail and contrast.

The CMYK color space is device-dependent, meaning that the exact appearance of a color can vary slightly depending on the specific inks, paper, and printing conditions used. This is in contrast to device-independent color models like sRGB, which aim to represent colors consistently across different devices. Therefore, color management is important when working with CMYK to ensure accurate color reproduction.