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Rembrandt Process

cylinder, printing, lines and machine

REMBRANDT PROCESS An adaptation of the photogravure process to rotary mechanical printing, invented by Karl Klic, and worked in England since about 1895 by a Lancaster firm. The details of their method have been kept secret, but it is assumed that a print on carbon tissue is made under a trans parency in the usual way, except that, either before or after the print of a picture is made, the tissue is exposed under a negative line screen—that is, a screen with transparent lines, instead of the network of black lines used in the half-tone process. The printed tissue is squeegeed on to a copper cylinder, and there developed with hot water as in the carbon pro cess. After being dried, the image is etched through by means of ferric perchloride, as in the ordinary photogravure process, the cylinder being rotated in the bath, and solutions of different strengths being used. On the resist being cleaned off, the copper cylinder is seen to have on it an intaglio etching which varies in depth, being deepest in the shadows. The image is cut up by thin lines formed by the screen, and the square spaces between the lines serve to hold the ink better than would the grain of the ordinary photogravure plate. The cylinder is mounted in a machine similar to that used by wall-paper or calico printers. Above the copper

printing cylinder is the impression cylinder, covered with an endless blanket, and below the printing cylinder is an inking roller running in a trough of thin ink. A steel knife-edge presses against the printing cylinder and wipes off the ink from the surface, whilst leaving the ink in the hollows of the engraving. Paper in a long band is drawn from a reel through the machine, passing between the printing and impression cylinders, and thereby being printed. After leaving the machine, the paper is led off to a drying-room, where it is suspended in festoons, or it is rewound on another reel, or it may pass straightway into a cutting machine.

Recently the process has been developed into colour printing under the name of mezzochrome, and some very fine results have been produced. Whether the foregoing correctly describes the Rembrandt process or not, it is known that several other firms have imitated the results in this way, notably Bruckmann in Munich, Lowy in Vienna, and Saalburg in America. The pro cess is also known under the name of mezzotinto gravure, altogravure, Similiheliogravure, and Vandyck-gravure.