The principle of printing color reproduction

Color image printing is mainly used to print colorful images after overprinting the color separations with dot. Yellow, magenta, cyan, and black colors are superimposed on one another, and there is a side-by-side relationship. In this way, both the principle of subtractive coloration and the overprinting portion of the additive dots on the dot are used in the blending of the dots. Each color ink is like a layer. Filters. The same principle as the color subtracting method described above is the same. As shown in the figure, the magenta ink selectively absorbs the green light, and the cyan ink absorbs the red light. Finally, only the blue light is reflected, and a blue sensation is formed in the human eye. This is the principle of the subtractive color method.

In the juxtaposition of dots, because the dot is very small, the human eye can not distinguish each dot individually. The light reflected by dots of different colors mixes and stimulates the human eye and forms a mixed color effect. This is the principle of color additive color method.

In the printed image, yellow, magenta, cyan, and black are mixed in various ways.

The role of the black version

Only the three primary colors of C, M, Y should be able to reproduce a variety of colors (including black), but due to the limitations of printing inks, paper, and printing processes, virtually all colors cannot be reproduced through the three primary colors, but only a part, mainly insufficient. It is only the three-color mixed image that has insufficient contrast and insufficient density. Therefore, it is necessary to supplement the color and gradation of the dark tone portion of the image with the help of the black edition on the basis of the three primary colors, so as to increase the depth level of the thick color portion. The three-dimensional image.

In addition, the addition of the black version can also mask the neutral gray cast in the printing process, improve the mid-to-dark tone of the achromatic layer, and stabilize the gray balance.