Tone-reproduction in Halflone-engraving.

Several steps in the production of halftone engravings lead to distortions in the tone scale so that laborious and time-consuming corrections are necessary. The Dutch Institute for printing and Allied Industries set up an inquiry in Dutch photoengravers' shops to locate these tone-distortions and to estimate the extent of their influence. It is shown that production methods are rather unreliable, especially in halftone photography. Further that at some stages of the process people are used to a considerable quantity of superfluous work; e.g, deep-etching of halftone blocks is not necessary; re-etching is often extended far too much. Relations are derived between ton-value in several phases of the process. A few suggestions for improvements are made.