Letterpress printing plate having printing surfaces with a low surface tension, and method of making

摘要

A letterpress printing method is disclosed wherein a printing plate, having a plastic surface with a critical surface tension in the range of approximately 18-35 mN/m, is engraved or otherwise provided with raised ink-bearing impression sites and the printing plate is used for printing in a letterpress printing machine. As examples, the plastic surface of the printing plate may comprise a fluoropolymer, polytetrafluoroethylene or a copolymer of tetrafluoroethylene and hexafluoropropylene. The low surface tension is shown to enhance the printing quality in this environment.