MULTILAYER PRINTING PLATE AND PREPARING SAME

摘要

Multilayer printing plates having layers with differing moduli are made by exposing through a photographic negative a plurality of liquid layers of different photopolymerizable compositions. The layer compositions contain polymerisation inhibitor and photoinitiator. The amount of photoinitiator in the base layer 2 is greater than that in printing layer 3 and the layers have moduli differing by at least 50 p.s.i. Plates having a hard upper layer and a soft base do not broaden at the relief surface until the softer base layer is highly compressed.