Main reason: UV varnish is not viscosity enough, cause the printing coating is too thin.The surface of the printed product is greasy;  Ink surface "vitrification", improper affinity with gloss oil;  Ink surface containing anti adhesive material (such as silicone oil, dusting) too much;  Coating roller is too thin; 

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.