Main reasons: UV varnish viscosity is too high; Pressure nonuniformity; Coating quantity is too large; The leveling of UV varnish is poor; Paper is not smooth, absorption is too strong; UV varnish has poor surface peaceability.

Solution: reduce UV varnish viscosity; Reduce the amount of coating,Uniform pressure adjustment; Add a small amount of leveling agent; Corona treated the printed surface to increase the affinity of UV varnish to the surface.