Color shift with PDF files

Posted by: Jim Dornbos

Color shift with PDF files - 08/09/19 04:14 PM

I have a background PDF image that has a dark blue band of color - specified as 100/60/0/60 (CMYK). It's defined as a CMYK color in the PDF. When I create my merged vdp file for print through PP Production/Workflow, the color is changed to 100/83/40/22. I need some help figuring out how to get the same color out as I am putting in.

When downloading the PDF to the printer originally, Color conversion is set to "As is", Image Quality is set to "Photo" and Image Compression Level is set to "100".

My digital action used to generate the PDF has Job Options set to Color Images compression = Auto, Downsampling = None and resolution = 2400.

Any thoughts on what other settings can be tweaked to generate PDFs with the colors unchanged?

For what it's worth, I can take that same PDF, save the page in question as an EPS and when using that as the background image - color out exactly matches color in. Not a real solution, but the best we have been able to figure out in a pinch.

Posted by: Yannick Fortin

Re: Color shift with PDF files - 08/09/19 04:41 PM

Because PlanetPress produces a PostScript job, any PDF in the input is first converted to an EPS internally. That conversion is done with a set of default values that usually give the best output.

The operative word here is *usually*. In some cases, another set of conversion parameters might be preferrable.

Unfortunately, the software doesn't allow those parameters to be changed.

The workaround that you have found, to use an EPS instead, is indeed the right solution for cases where the automatic conversion from PDF isn't optimal.
Posted by: Jean-C├ędric

Re: Color shift with PDF files - 08/09/19 04:45 PM

Can you confirm that you data file is a PDF or is it a PDF image that you add?

If it is a PDF data file as input, then we might have a workaround for you.
Posted by: Jim Dornbos

Re: Color shift with PDF files - 08/09/19 04:53 PM

The PDF is an image built as part of the template. The data source is *.csv.

Posted by: Jim Dornbos

Re: Color shift with PDF files - 08/09/19 05:00 PM

Thanks, Yannick. It seems like a straight pass-through of input CMYK values to output CMYK values might be an improvement to the existing method. If any other options or ideas come to mind as a way to automatically handle this, please pass them along.