Patent model for printing photomechanical plates

This patent model demonstrates an invention for methods of making photomechanical or other prints resemble original photographs. The invention was granted patent number 493850.

Tonal photomechanical reproductions had an objectionable coarseness because of the perceptible pattern of the halftone screen. By this invention, screened plates-either bearing an image or blank-were printed several times slightly out of register with each other, softening the effect of the screen. The key impression of the image would be made first in a dark ink with a heavy body, and then the other impressions in paler or lighter-bodied inks. To imitate sepia photographs, later impressions were made in brown tinted inks.

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