Method of planographic printing with a reusable substrate

摘要

A direct-to-plate method of lithographic printing is disclosed which enables to recycle the lithographic substrate of the printing master. The method comprises the steps of(a) making a negative-working imaging material by coating on a hydrophilic substrate a coating solution comprising hydrophobic thermoplastic polymer particles and a hydrophilic binder;(b) making a printing master having ink-accepting areas by image-wise exposing the imaging material;(c) applying ink and fountain solution to the printing master;(d) removing the ink-accepting areas from the printing master by supplying an alcohol and preferably also an alkanolamine.The above steps are preferably carried out on-press.