DCS is inherently a separated format, and, as such, in most workflows you can't trap it. The system can use OPI to recombine separated DCS files that are referenced in composite PostScript.
OPI-ing a DCS in composite PostScript is desirable because the system recomposites the DCS on OPI into the composite page, allowing you to use trapping.
In order for Prinergy Evo to recomposite the DCS, in the Refine to PDF process template dialog box, Normalize section, select the Do OPI Image Replacement check box and in the Search Path Order box, define the OPI replacement search paths. If you do not enable OPI replacement, Prinergy Evo produces a low-resolution preview if one exists in the DCS control file.
Note: You don't necessarily always want to trap DCS, particularly if the DCS files are copydot or otherwise pre-screened. In that case you never want to trap them. However, if your linework DCS contains linework, 1-bit, continuous tone, or vector information and you want to trap the DCS files against other page content, for example, type or linework elements, recompositing the DCS enables you to trap the separated input.
See also Copydot scans and other DCS files
QuarkXPress, Photoshop, FreeHand, and Illustrator and DCS files
When saving DCS files from Photoshop and placing them in desktop software such as Illustrator software or QuarkXPress software, save the DCS file as DCS 2-single with either a grayscale or a color preview. The system merges high resolution DCS data into composite thin PostScript.
Using QuarkXPress OPI or a color control OPI to create raster DCS, you can merge high resolution images into composite PostScript, via the Refine to PDF process template, OPI replacement feature. However, in order to do this, the DCS file must have a preview.
Freehand and Photoshop will include OPI comments for TIFF only (not EPS). To perform OPI on an EPS (including DCS) input file, create a sample of the file using an image sampler.
If you want to place partial-page raster DCS files in software such as QuarkXPress software or Adobe PageMaker , and save as a composite thin PostScript file, you can then submit the PostScript file for processing. When the system fattens the file, it composites the DCS.
High-resolution files must be in an OPI folder and the OPI replacement search path must be defined in the Normalize section of the refine to PDF process template in order for the system to fatten the file and composite the DCS 1 or DCS-2 files.