Paper absorption and color rendering

Absorption of paper refers to the absorptive capacity of the paper to the binder and its solvent in the ink and is usually expressed as a percentage. Absorption of paper is also called ink absorption. Its strength is very sensitive to the appearance of printing hue and the glossiness of the ink layer. Paper with strong ink absorption, the hue of printed ink is easy to fade, and the ink layer lacks glossiness. In addition, since the binder in the ink is mostly absorbed by the fibrous tissue of the paper, the pigment particles are not sufficiently protected and the ink film on the print is not firm, and the phenomenon of “powdering” of the print is likely to occur. Conversely, if the ink absorption of the paper is too weak, the ink layer of the printed product will not be adhered securely, and the print will not be easily dried, which will easily cause the back of the printed product to become dirty. Therefore, according to the characteristics of the use of printed materials, select the appropriate absorption of paper for printing, in order to better ensure the printing quality. For example, newspapers should use strong absorbing newsprint to meet the characteristics of high-speed, emergency, and economical use. The fine print products, the color should be bright to require weak paper absorption, such as glass cards, coated paper and so on. Among the paper properties that affect the color rendering effect of printed products, the most prominent is the glossiness and absorbency of the paper. The combined effect of the paper's absorbency and gloss on the ink effect of the print is called the surface efficiency of the paper. It can be calculated by the following formula:

PSE(%)=(100-A(%)+G(%))/2

In the formula: PSE stands for the surface efficiency of the paper; A is the ink absorption capacity of the paper; G is the glossiness of the paper. Process testing can show that when the surface efficiency of the paper is high, the color intensity of the ink is the highest under the same process conditions, while the color shift and gray scale are the minimum. The research and testing of the surface efficiency of paper is an important part of realizing the data and standardization of the process. It is of great significance to better correct color cast and to ensure the quality of product printing. Therefore, it is necessary to correctly understand and understand the performance of paper on printed products. The effect of color rendering is undoubtedly beneficial.