In printing terms, we often hear the terms four-color printing and spot-color printing, and they are widely used. But most people don't know when to choose four-color in actual production, and when to choose spot color. Today, I will discuss both of them from concept, difference to application.

Four-color printing is to use CMYK (cyan, magenta, yellow, black) four-color overprinting of the required colors. In layman's terms, it is to use the different superposition of these 4 colors to get the desired color. As long as the color has a gradient, it is printed in four colors. Four-color printing is superimposed by dots. You can see different colors with a magnifying glass.

It is suitable for products that are taken by color photography to reflect the rich and colorful color changes in the natural world, color art works of painters, or other pictures containing many different colors, due to process requirements or economic benefits For the consideration, the color separation must be scanned by an electronic color separation machine or a color desktop system, and then a four-color printing process is used to complete the reproduction.

Spot color printing refers to a printing process that uses inks other than the four-color inks of yellow, magenta, cyan, and black to replicate the colors of the original. Its process is often used in packaging printed to print a large area of background color. It is a single color, no gradation, the pattern is solid, and the dots cannot be seen with a magnifying glass. (Generally speaking, the cost is slightly higher for it.)

Spot color printing is suitable for products, part of packaging products or book covers and album covers are often composed of uniform color blocks of different colors or regular gradient color blocks and text. These color blocks and text can be overprinted with four primary colors after color separation. It is also possible to mix spot color inks, and then print only one spot color ink on the same color block. In the case of comprehensive consideration of improving the quality and saving overprinting times, spot color printing is often used. Packaging printing often uses spot colors to print large areas of background colors. 

What is the difference between the two printing visual effects?

Spot color printing has lower color brightness and higher saturation; spot color blocks with uniform ink color are usually printed in solid, and the ink volume should be increased appropriately. When the thickness of the ink layer on the layout is large, the change of the ink layer thickness will affect the color change. The sensitivity will be reduced, so it is easier to get a uniform and thick printed effect.

The color block printed by the four-color printing process is easy to change the color intensity due to the change of the thickness of the ink layer and the change of the print process conditions. Changes in the degree of dot expansion, resulting in a change in color. Therefore, it is not easy to achieve the uniform ink color effect with the color blocks printed by the four-color printing process.

From the perspective of economic benefits, it is mainly to see whether the use of spot color printing technology can save the number of overprints. Because reducing the number of overprints can not only save printing costs, but also save the cost of pre-press production.

If the picture of a certain product has both a color gradation picture and a large area background color, the color gradation picture part can be printed in four colors, and the large area background color can be printed in spot colors.

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