Xerox P8EX Spire CXP8000 Color Server - User Guide - Page 56

42 Chapter 3 - Working From a Client Workstation Table 4: PPD parameters PPD Parameter Black Overprint Printing Options Yes provides better printing quality (as in FAF) and a richer, deeper black with the underlying CMY values equal to those of the printed background. As a result, misregistrations are not visible. Black Overprint ensures that 100% black text prints cleanly within a tint or picture area. Occasionally, white lines may appear around black text and the text may appear less dense than desired as a result of misregistration between color separations. With Black Overprint, the Pure Black Text / Graphics option is automatically activated and there are no knock-outs under the black text. However, a knock-out occurs when you print only the topmost color. This results in less color density and can cause misregistration if separations are not perfectly aligned. No leaves the job as is. PS Overprint PS Overprint offers the option to use the overprint, which exists in the PostScript file. It also determines whether the DTP application PS Overprint settings are honored in the RIP. Spire CXP8000 color server settings override PS Overprint commands from DTP applications. For example, if PS Overprint was set to Yes in a DTP application, selecting PS Overprint No in the Spire CXP8000 color server results in no overprinting. The Spire CXP8000 color server can not create PS Overprint that is not predefined in the file. Selecting PS Overprint Yes for a file that has not had overprinting defined in a DTP application does not result in overprinting. Yes (default) instructs the RIP to use the overprint information that exists in the input PostScript file. Also, if PS Overprint is applied in a DTP applications, it is implemented by the Spire CXP8000 color server. Background colors are not knocked out. For example, in the case of a yellow triangle overlapping a cyan circle, selecting Yes results in the overlapping area turning green. This is not seen on the screen, only in print. No ignores the overprint information that exists in the input PostScript file. Background colors are knocked out and only the top most color parts are seen on the screen in your DTP application. For example, in the case of a yellow triangle overlapping a cyan circle, selecting No results in the cyan background being knocked out, so only the yellow is printed.