Abstract: Plural images and plural register marks are printed on a photosensitive material with an original plate including an original image and register marks. Two kinds of masks are prepared before the printing: a photocomposing mask for masking the original image and the register marks on the original plate, and an exposing-out mask for masking the images and the register marks on the photosensitive material. First, the plural images and the register marks are printed on the photosensitive material while overlaying the original plate with the photocomposing mask by a photocomposer. Secondly, the photosensitive material is exposed with the exposing-out mask overlaid. Even if the plural images complementary are to each other, the total procedure can be performed easily while using the two masks. The two masks can be fabricated easily on the basis of the shape of the original image and of the positions and orientations of the plural images on the photosensitive material.