PURPOSE: To prevent the generation of a thin line, and to reduce the number of stages and to shorten a time by laying out an image of an original which are formed in positive form on transparent film pieces over a transparent film which is as large as a finished print, and superposing a light divergent transparent plate thereupon and exposing it to a photosensitive material.

CONSTITUTION: The image of the original 2 is formed in positive form on the transparent film pieces 14, which are laid out on the transparent films 15 by using adhesive tapes, etc., and lightdivergent transparent plates 22 are then stacked thereupon to expose a photosensitive material to the images of the transparent films 15, thus forming a plate 17 for printing. Consequently, a shadow due to the thickness of the film pieces 14 and adhesive tapes 16 which is not present on the original is prevented from appearing on printing paper 6. Further, a PS plate, etc., are exposed and etched by using the transparent films where the film pieces 14 are laid out to make a flat plate easily, thereby obtaining a polychromatic finished sample speedily. Further, each film piece 14 is peeled off and stored for reuse.