Brief Analysis of the Different Tones of Spot Colors in Digital Printing

Purposes: In digital printing, four colors are used to simulate spot colors for printing, when the spot color level changes, the color matching ratio of four colors will change, not just the change of the dot, which will directly affect the hue value, that is, there will be color deviation. This paper will use the method of spot color matching to output the gradual change of spot color and analyze the change of their hue value. Method: Under the condition of ideal color state of the equipment, the output of four-color and spot color matching is carried out, the data is measured by LCH color space, the theoretical value is obtained from the software, and the actual value is measured by Xrite eXact spectrometer and analyzed. Result: The smaller the color difference value after spot color matching, the hue value H is closer to the theoretical value, and the hue of different order is stable. When the matching effect of spot color is not good, the color Angle of different order fluctuates greatly, and the color is gradually discolored and unstable. Conclusion: When the spot color is applied in a gradual gradient, it is necessary to avoid the tone range of 10%-30% as far as possible, and the probability of jumping in the hue value is high, which is easy to produce color bias.