| 摘要 |
PURPOSE:To obtain a reproduced picture having a stable quality and a wide gradation reproducing area by preparing a composite positive by photographing double two kinds of net pictures on a film, with regard to a magenta form and a cyan form, executing the printing onto a form material by using said composite positive, executing the photoengraving, and photoengraving other form onto the form material by using a positive. CONSTITUTION:In case of photoengraving of a yellow form and a black form, first of all, a continuous tone decomposition form 1 is printed to a photosensitive material 3 through a usual line number net screen 2a, and a printing form 6a is obtained through a usual line number net screen negative 4a and a usual line number net screen positive 5a. In case of photoengraving of a magenta form and a cyan form, printing form 6b is obtained through the usual line number net screen 2a, a thin line net screen 2b, and a composite net positive 5b. As for the printing form 6a, a net point on a printed matter cannot be discriminated with the naked eye. As for the printing form 6b, a moire is prevented by net-photographing the bright part through the half tone part by a thin line screen, and also the net point of the bright part cannot be seen. As for the dark part, a picture density can be reproduced enough by combining a net-photographing by the usual line number net screen 2a. |
