Final answer:
In the CMYK color process, the 'K' stands for Key, which refers to black. It is part of the subtractive color process used in printing that combines cyan, magenta, yellow, and key (black) to produce a wide range of colors on paper.
Step-by-step explanation:
In the CMYK color process, 'K' stands for Key, which refers to black. This term originated from the days of four-color plate printing where the Key plate was the plate that held the detail or the 'key' imagery which was often rendered in black. In terms of color mixing, CMYK is used in printing to create a wide range of colors through a subtractive process. Cyan, magenta, yellow, and key (black) inks are combined in varying degrees to produce different colors, and when all are mixed together in the right proportions, they theoretically result in black.
The CMYK process is well-suited for creating images on paper and is commonly used in inkjet printers. These printers have a black ink jet and three other jets for the primary colors of cyan, magenta, and yellow. These primary colors can combine to make secondary colors, such as green from cyan and yellow, through subtractive color mixing, as opposed to additive color mixing which uses red, green and blue as primary colors seen in digital screens.