Printing process is an important part of packaging production, and it is inevitable to encounter printing color difference and other related quality accidents in the printing process. What are the factors causing printing color difference?

1、紙張白度：白度不同的紙張，對印刷墨層的顏色顯現(xiàn)有不同的影響。對同一種白板紙而言，白度不同，印刷墨層的顏色差異主要體現(xiàn)在專色墨中黑墨成分的多少，尤其是對明度在70以上的顏色，影響特別明顯，造成專色墨的配比差別很大。

1. Paper whiteness: paper with different whiteness has different effects on the color display of printing ink layer. For the same kind of whiteboard, the whiteness is different, and the color difference of the printing ink layer is mainly reflected in the amount of black ink in the spot color ink, especially for the color with lightness above 70, resulting in great differences in the proportion of spot color ink.

2、表面處理對顏色的影響

2. Effect of surface treatment on color

包裝類產(chǎn)品的表面處理方式主要有覆膜、上光等。印品經(jīng)過這些表面處理后，會有不同程度的色相變化和色密度變化。這些變化分為物理變化和化學(xué)變化。物理變化主要體現(xiàn)在產(chǎn)品表面增加了鏡面反射和漫反射，這對色密度有一定影響。

The surface treatment methods of packaging products mainly include film coating, polishing, etc. After these surface treatments, prints will have varying degrees of hue changes and color density changes. These changes are divided into physical changes and chemical changes. The physical change is mainly reflected in the increase of specular reflection and diffuse reflection on the product surface, which has a certain impact on the color density.

3、撤淡劑對顏色的影響

3. Effect of desalting agent on color

撤淡劑是一種油膏狀的無色透明物質(zhì)，在專色印刷中主要起沖淡顏色的作用。撤淡劑的加入量不同，對色相的影響也不同，尤其是藍色表現(xiàn)得明顯。

Diluent is a colorless transparent substance in the form of ointment, which mainly plays the role of diluting color in spot color printing. The influence of different amount of diluent on hue is also different, especially blue.