Fingerprints were found on the printed products after glazing, especially when the black ink was glazed. This is because varnish often adds some additives to improve the varnish properties, such as defoamers, leveling agents, etc., they do not participate in the curing cross-linking reaction, and will eventually be absorbed by the substrate, or may be removed after curing. To the surface of the coating. If the varnish is not stabilized in the coating, it will migrate to the surface of the coating, forming an uncured layer that will leave a fingerprint when it is touched. Solution: Ensure that the coating is completely dry and reduce the migration of residues to the surface of the coating.