What are the main factors influencing the color offset printing ink color 

From the point of view of the paper, the effect of spot color ink color factors probably have three: 1, paper whiteness absorbent paper, paper gloss and smooth degree, the some factors of expansion factors with influence the ink color. 

1, paper whiteness 

The white degree is different (or with a certain color) of the paper, the ink layer of the color of the show have different effects. In a white paper, whiteness, printing ink layer of color difference mainly reflected in the number of spot color ink in black ink composition, especially in more than 70 to the lightness color. The most notable effect, resulting in a spot color ink formulation varies greatly. Therefore, in the actual production should be as far as possible the use of the same white paper printing, in order to reduce the impact of paper whiteness on the printing color. 

2, absorbent paper 

A printing ink to the absorption of different paper in the same premise, will have a different print gloss. The structure of the paper determines the paper surface there are concave and convex formed by the plant fiber, in order to make the paper get a good average degree of smoothness, generally to the paper surface coating of different thickness of coating. The nature and thickness of the coating determines the ink absorption ability of the paper surface. Absorption ability is different, must make the color of printing ink layer difference. Compared to non coated paper and coated paper and black ink layer will become dark, no gloss and color ink layer will drift, by cyan ink and magenta ink deployment of color performance significantly. 

3, paper gloss and smoothness 

The gloss of printed matter depends on the gloss and smoothness of the paper. The surface of the printing paper belongs to the semi gloss surface, in particular, the coating paper. 

In the color printing, when the light at 45 degrees to the incident angle to the paper surface, about 4% of the light will be reflected off, this is the first layer of surface reflection light. And the rest of the incident light through the ink layer, through the selective absorption of ink, and then reflected through the ink layer, into the human eye, by the human eye perception, this is the color we observe. If the paper's gloss and smooth degree is higher, the first layer of surface reflection light is to do the specular reflection, not easy to enter the human eye, at this time the color of the observation is basically reflected through the ink layer. If the paper surface is coarse, low gloss, the reflection on the surface of the first layer light will occur diffuse reflection, at which point we can see that the color is produced by the colour, and the first surface reflection light mixed color. Because it contains white components, thus reducing the saturation of the colour, so that people observe prints when feeling lighter color, measured with a densitometer density values decreased, the brightness increased.