Participating Frequently

Answered

Placed PDF causes change in greyscale images

Forum|Forum|3 years ago
September 7, 2022
3 replies
718 views

I have a magazine design that is exported to PDF for a commercial printer to create proofs from. There are a number of greyscale images in the document that print fine for the most part. The only time they do not print correctly is when there is a placed PDF file on the same page (typically an ad). When this occurs the greyscale image that shares the page prints lighter than expected. All other greyscale images in the doc print fine, it is only when a placed PDF shares the page does the error occur.

My guess is that there is something in the placed PDF (it's color profile, transparency settings, black settings, etc.) that is affecting the greyscale images on those pages only.

Anyone have any ideas how to fix this?

This topic has been closed for replies.

Correct answer rob day

Completely understand, no worries.

From your description it sounds like the PDF "grayscales" have been converted to CMYK, which would account for the darker tonality, and the placed grayscales are making it through to the press sheet as black only. Normally placed grayscales preview as they would print on the CMYK black plate when Overprint Preview is turned on.

Usually there is no conversion on a PDF export, the exception would be if the PDF export was to a CMYK Desination profile that conflicts with the assigned document profile, or the Transparency Blend Space is set to RGB and the Export is to a flattened preset, e.g. PDF/X-1a. You should be able to see that on the press sheet with a magnifier.

Jumpenjax

Community Expert

Extract that page, open in photoshop, make sure you open in RGB or cmyk which ever you need. Then flatten and save as a tiff.

Lee- Graphic Designer, Print Specialist, Photographer

M

matthewr45162948Author

Participating Frequently

Unfortunately I cannot do this as all pages have to be released to the commercial printer as PDFs not tiff.

rob day

Community Expert

Hi @matthewr45162948 , can you share the PDF? You should be able to attach it to your reply.

M

matthewr45162948Author

Participating Frequently

Unfortunately I cannot due to client NDA agreements.

rob day

Correct answer

Community Expert

Completely understand, no worries.

From your description it sounds like the PDF "grayscales" have been converted to CMYK, which would account for the darker tonality, and the placed grayscales are making it through to the press sheet as black only. Normally placed grayscales preview as they would print on the CMYK black plate when Overprint Preview is turned on.

Usually there is no conversion on a PDF export, the exception would be if the PDF export was to a CMYK Desination profile that conflicts with the assigned document profile, or the Transparency Blend Space is set to RGB and the Export is to a flattened preset, e.g. PDF/X-1a. You should be able to see that on the press sheet with a magnifier.

Rishabh_Tiwari

Legend

Hi,

Thanks for reaching out. I found this similar discussion https://community.adobe.com/t5/indesign-discussions/placed-pdf-over-inking-on-export/m-p/12064895#M430596 which you can refer to and let us know if this helps or if you need any further assistance.

Regards

Rishabh

M

matthewr45162948Author

Participating Frequently

Thanks Rishabh -- while not 100% solved, this definitely seems to be related to the issue. Looks like it's something related to either the Transparency Blend Space in my InDesign doc, the transparency blend mode used by the advertisers to create their PDF ads which are then placed into the InDesign doc, or the transparency blend space of my final export.

Sign up

To post, reply, or follow discussions, please sign in with your Adobe ID.

Sign in to Adobe Community

To post, reply, or follow discussions, please sign in with your Adobe ID.

Scanning file for viruses.

This file cannot be downloaded