(1) The paper has high roughness and strong absorbency. For this type of paper, the amount of coating on the oil should be increased, the concentration of the oil on the surface should be increased, or a layer of coating should be applied before the finishing process, and then the line should be coated with light.

(2) The quality of the glazing oil is poor, and the brightness of the film itself is poor.

(3) Production process factors, including low concentration of glazing oil, insufficient coating and thin coating; Drying or low pressing temperature; The pressure is not enough to wait.

Mechanical factors. The compression zone is not enough gloss due to wear.