2

After exporting a file to PDF from InDesign to be imposed in Acrobat, we sometimes get unexpected color/appearance changes that are almost always easily solved by printing directly from InDesign. We don't print directly from Acrobat but drag-and-drop the PDF imposition file into the Fiery queue.

The unexpected results seem to happen only with more complex files that use transparency, though it might be something else also. Does anyone know why this kind of thing happens and any workarounds? Are there settings that can be modified in Acrobat to produce better results? The workflow here is PDF-based, so I don't know how to get around these color/appearance change issues that sometimes cause re-prints, etc. because they can sneak by unnoticed, or only show up while printing.

5

Acrobat (PDF) is a software RIP (raster Image Processor). So when you export as a PDF, you essentially create a file as if you were printing it to a non-disclosed printer. This means color settings and job Options when exporting to PDF matter.

When you print a PDF, it's already been processed so any printer RIP doesn't have to do anything but read the data and output. Whereas if you print an InDesign file, that file has to be processed via the printer's RIP.

It's nearly impossible to tell you why you are getting inaccurate color without actually examining files. A few things to check:

  • Is InDesign's Transparency Blending Space (Edit menu) set accordingly?
  • Are colors in the InDesign file RGB or CMYK?
  • Which color (CMYK/RGB) does your printer prefer receiving?
  • What are the job options when exporting to PDF?
  • Are job options set up to create a CMYK file when your printer prefers RGB data be sent? or vice versa?

I don't expect you to answer any of these. They are merely things to look for.

If you send CMYK data to a printer which prefers RGB data, color will shift. If you send RGB data to a printer expecting CMYK, then colors can shift.

If your InDesign colors are RGB and you export a PDFx file, then the PDF will be CMYK. Etc...

1

Your work might be made easier if you create PDF-X/1a documents out of InDesign. This would take care of some of the issues already mentioned. (of course, if you are in an X4 workflow, stay with that…)

  • Ill look into that. Ive known about PDF-X standards for a while but none of the companies Ive worked at ever used them, so not sure what the use might be. – Alex Monterville Dec 7 '17 at 13:56
1

The main cause of your problems are related to the way, your Fiery handles PDF files: Embedded controllers first convert PDFs to Postscript using EFI's own CPSI software before rasterizing the final output.

External Fierys are able to skip this step and RIP the actual output using an Adobe licensed library, called APPE.

This technique produces the same output as printing directly out of Acrobat. As a side effect, it is less error prone because color management can only be applied at one central point: The RIP itself.

Nevertheless, there are some rare cases, even APPE fails to render a job. That's why EFI made this feature optional.

But I strongly disagree that producing a PDF file does indeed rip it. Acrobat does rasterize parts of your PDF when printing (= producing a Postscript file) but the RIP itself still has to do some extensive tasks in order to rasterize it completely.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.