What is the color separation principle of printing plate?

When making a plate, the manuscript is divided into four colors: blue (C), magenta (M), yellow (Y), and black (K). What is the principle of color separation?

A: There are tens of thousands of colors on the screen in color drawings or color photos. It is almost impossible to print all these thousands of colors in a single color. The four-color printing method is used for printing. That is, the original is first color-decomposed and divided into four color plates of cyan (C), magenta (M), yellow (Y), and black (K), and color synthesis is performed at the time of printing. The so-called "separation" is based on the principle of subtractive color, the use of red, green and blue color filters for different wavelengths of the selective absorption characteristics of the color light, and the original is decomposed into yellow, goods, blue three primary colors. In the color separation process, the color light absorbed by the color filter is the complementary color light of the color filter itself, and the negative film forming a black and white image on the photographic film is re-screened to constitute a negative point of the screen, and the copy is finally printed in a variety of colors. Printing plate. This is the earliest photographic separation principle.

Due to the development of printing technology, we can now separate, sample, and convert the color of a manuscript into digital information by using a prepress scanning device. That is, the color of the manuscript is divided into red (R) and green (G) by the same method as photolithography. Blue (B) three colors, and digitized, and then use a computer to mathematically calculate the digital information into blue (C), magenta (M), yellow (Y), black (K) four-color information.

Source: Shenzhen Printing Network