A Comparison of Powderless Etching Results on Photoengravers' Metals.

Existing practices in the printing industry make it desirable to use type and halftones from a single source as copy for reproduction by offset lithography and by letterpress from etched or washed-out printing plates. Many statements made regarding the degree to which the metal etching processes result in printing area loss are contradictory. A comparison is made here of results from etching type to printing depth on zinc, magnesium and copper by the appropriate one-bite etching processes. Area losses, as well as contour and smoothness of sub-surface structure are compared. The results indicate that the goal of using a single negative for offset lithographic reproduction of type or for etched metal reproduction is close to realization.