Four-color printing Four-color printing is to use CMYK (cyan, magenta, yellow, black) four primary colors to overprint the color that customers need. In popular terms, it is the use of the different superposition of these four colors to get the required color, as long as the color has a gradual change is a four-color overprint. Four-color printing is superimposed with dots, and if you use a magnifying glass you can see dots of different colors. Spot color printing Spot color printing refers to the printing process of using other spot color inks other than yellow, magenta, cyan and black ink to reproduce the color of the original manuscript. In packaging printing, spot color printing process is often used to print a large area of background color. Spot color printing is a single color, no gradient, the pattern is ground, and the dot is not visible with a magnifying glass. Spot color ink Refers to a pre-mixed specific color ink, such as fluorescent pink, reflex blue, metal gold and silver ink, etc., it is not overprinted by CMYK four-color, color means accurate color. Spot color ink has three characteristics: 1. Accuracy Each set of colors has its own fixed hue, so it can ensure the accuracy of the color in printing, thus solving the problem of color transmission accuracy to a large extent. 2. Facticity Spot colors generally define a color by a solid color, no matter how light that color is. Of course, it is also possible to Tint the spot color to render any shade of the spot color. 3. Wide color gamut The color gamut in the color library is so wide that it exceeds the RGB representation gamut, not to mention the CMYK color space, so there is a large part of the color that cannot be rendered with CMYK four-color printing ink.