The main reason: UV varnish is not viscosity enough, cause the printing coating is too thin; Excessive dilution of ethanol, toluene and other non-reactive solvents; The gloss of curable resin itself is not enough; Paper absorption is too strong; Roller is too thin to transfer enough light oil. 

Solution: take necessary cleaning measures for the printed products which to be glazed; Properly adjust the viscosity of light oil; Deploy the type and amount of gloss additives, can add a small amount of wetting agent; The surface of the printed matter can be wiped with a 2% alkali solution.