| 摘要 |
<p>Halftone printing is carried out by printing a first impression in entirely with a solid density of good render-ability from the middle-tone part to the light-tone part in a printed matter and printing at least a second impression, superposed over the first impression, with a printing plate lightly and supplementarily expressing only the parts of high dot density of the printed matter. A set of press plates for carrying out this printing process is also provided. A set of plates includes a first plate which has been contacted photoprinted with a screened film made from a transparent or reflecting original and at least a second plate adapted to express somewhat lightly and supplementarily only parts of high dot densities (%) of the first plate. If desired a third plate can be used to express more lightly than the second plate and supplementarily only parts of higher dot densities (%) of the second plate.</p> |
