THE SHADOW OF A SIGN
For purposes of reproduction two processes depending on photography have almost entirely superseded the older methods of etching and wood engraving. These photo-mechanical processes, as they are called, are far more rapid and much cheaper, and are, in addition, more accurate. In photo-gravure the photographic image—copied by photographing the original—is transferred to a copper plate and the plate is automatically etched in an acid bath to varying depths, depending on the depth of shadow in the original. This plate is then inked all over, the ink being worked into the depressions in the copper, and the surface ink wiped off. A sheet of paper is brought into contact with the plate under heavy pressure, and, being forced into the hollows of the copper and taking up the ink from them, a print results. In the less beautiful but cheaper and more rapid half-tone process the copy is made through a cross-ruled glass screen, the image being thus broken up into a series of dots. The image so obtained is transferred to a zinc plate, which is etched in an acid bath or with an acid spray. The dots serve to protect the zinc from the action of the acid.[A] The finished plate shows an image consisting of dots with hollows between them, the dots being large and near together in the shadows, small and far apart in the lights. This plate is inked with a roller, and a sheet of paper, lightly pressed against it, takes up the ink to form a print. Thus it will be seen that photo-gravure is an intaglio (cut-in) process, and half-tone a surface-printing process.
[A] See cut on page 9.
Photographic Illustrations
From a platinum print by W. E. Macnaughton
SCENE ON THE CONNECTICUT RIVER
Photography has not only superseded manual processes for reproduction, but has also largely replaced them for purposes of illustration. Practically all news illustrations are now made by photography, which is also extensively used for advertising work. To a less extent it is employed for fiction illustration, admirable work having been done in this field by Clarence H. White, Karl Struss, and Lejaren à Hiller. It does not, however, seem probable that photography will ever entirely replace draughtsmanship for the illustration of fiction, since the very strength of the camera,—that is, its surpassing power of rendering accurately the outlines and gradations of natural objects,—operates as a severe limitation in the case of original, imaginative work. It is difficult to conceive of “The Fall of the House of Usher” or “The Rime of the Ancient Mariner” being satisfactorily illustrated by photography, and if, for instance, “Le Morte d’Arthur” were made a photographic subject, the cost of models, costumes and scenery would probably be excessive.
From a carbon print by H. Y. Sümmons