Product

Platform

Operating system

Error

Symptoms

Cause

Solution

We now have all of the tools in place and available to be able to tell customers how to make a grayscale dropshadow overprint other colors or raster data in a PDF file.

Note: This workaround will only work when you have a black only drop shadow on a background that does not contain any black. If the background and the shadow have any common separations, it will not work.

Enabling technology:

- The Prinergy Color Matcher

- PitStop 4.05 (4.03 does not work)

How does it work?

The drop shadow must be either an Illustrator type gradient or a Photoshop raster image defined as grayscale. (One bit shadows already work.) Then the PDF or PostScript that contains these items MUST be run through the Prinergy Color Matcher. The Color Matcher changes the color in the shadows from DeviceGray to a K only monochrome object. Then the user can open the PDF file, select the shadow objects with the PitStop 4.05 selection tool. Choose CMD-I or CLT-I. To get to the information window for the object, select the Prepress Tab and then the overprint Tab and if necessary set the object fill to overprint. It may not be necessary in all cases to change the object to overprint. It may already be set to do so by the Color Matcher.

Why does the file have to go through the Color Matcher?

DeviceGray images or objects cannot be assigned the Overprint attribute. Therefore, the Prinergy Color Matcher takes all DeviceGray objects and converts them to (Black) K monochrome data so that the overprint operator may be set.

How will it preview in Acrobat?

Since Acrobat cannot preview translucency, the shadow and the area around it will appear as a white knockout. You can verify the result with PitStop or visually with Separation Viewer and ultimately Creo VPS viewer on the Macintosh.

TIP: It is recommended that the user enable the PitStop wireframe view mode for selecting objects, then change back to the full preview mode to confirm the selection.

Special Notices: All files refined in Prinergy should be done so with the Color Matcher Enabled. As part of producing reliable PDF Digital Masters the Prinergy system fixes common color problems that affect trapping and other imaging issues as part of the Color Matcher Job ticket. These fixes have no visible interface and execute on all files passed through the Color Matcher.

Permanent fix:

See also

Keywords

color, PDF

Technical contact(s)

James Bredenhof

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Date submitted