The Preparation of Drawings and Other Illustrations for Photo-Reproduction (Classic Reprint)

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Excerpt from The Preparation of Drawings and Other Illustrations for Photo-ReproductionWhen an author or publisher wishes to make sure of a facsimile reduction of as perfect a line drawing as is needed for his-purpose, he will have it reproduced by photo-lithography or by photo engraving on zinc. Photo-lithography is generally employed for making large-sized illustrations for folding sheets and insets, which cannot very well be handled economically by the ordinary printing press. The originals require the same finish as those used for the zinc process. The photographs, reduced to the desired size, are transferred to a polished lithographic stone, which, after being re etched, is ready to print from in the lithographic press. Original photographs may also be repro duced in this way, giving the same general result as by the more familiar half-tone process, de scribed further on.A line engraving on' zinc is produced by first printing a reversed negative, made from a large original, upon a polished and sensitized zinc plate. When inked by means of a printing roller, the ink adheres to the black lines of the plate, corresponding to those on the original drawing. Powdered resin is then sprinkled over the plate. It adheres to the ink lines, and on being heated it melts and forms a protective coating against the etching solution. This solution is next poured over the plate and is allowed to remain until it eats out enough of the metal between the lines to leave the latter in clear relief. More metal is then removed or routed from between the lines by means of a finishing tool. Finally, the zinc plate is mounted upon a wood block and isready for use in the printing press.About the PublisherForgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.comThis book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully, any imperfections that remain are intentionally left to preserve the state of such historical works.