Incorrect colour management of linked files?

[MJP]

When exporting a document to PDF from Publisher for printing via a professional RIP (ColorGATE Production Server 10),  the colours of linked Designer files (either PDF or afdesign) do not match those of text and graphic elements generated directly within Publisher itself with the identical RGB values.

The document settings, working spaces and profiles are identical in both Designer and Publisher (ProPhoto RGB 16-bit), as are the PDF export settings. Curiously, the various elements in the document display identically in both Publisher and in Acrobat 10 when exported as a PDF, but the elements linked from the original Designer documents exhibit a colour shift when previewed and printed from the RIP.

Attached are the following screenshots:

Designer.jpg: The original text generated in Designer
Publisher.jpg: The composite Publisher document with the linked Designer text overlaid on a solid square of the identical colour generated directly in Publisher.
Acrobat.jpg: The composite Publisher document exported as PDF and viewed in Acrobat 10
ColorGATE RIP: The exported PDF as previewed and printed via the RIP

I have tried various export settings but have been unable to establish the cause, although the issue is entirely repeatable. I do have a tentative hypothesis that the linked elements may somehow be being exported with 'preserve numbers' rather than with the correct profile and conversions but cannot presently confirm this.

I would be grateful for any advice in case I may have missed a setting somewhere, or confirmation if this is indeed a bug.
 

 

 

Edited January 18, 2021 by MJP
Inadvertently posted before complete

[MJP]

Apologies, the screenshots appear to have uploaded without titles. In order of display, they are:
Acrobat.jpg
ColorGATE RIP.jpg
Designer.jpg
Publisher.jpg

[Gabe]

Hi @MJP,

Welcome to the forums. 

On 1/18/2021 at 3:15 PM, MJP said:

The document settings, working spaces and profiles are identical in both Designer and Publisher (ProPhoto RGB 16-bit), as are the PDF export settings. Curiously, the various elements in the document display identically in both Publisher and in Acrobat 10 when exported as a PDF, but the elements linked from the original Designer documents exhibit a colour shift when previewed and printed from the RIP.

This makes me thinking it's something that the RIP does not like. Have you tried contacting them and see why they are the only one who print/preview it differently? Since our app (and Acrobat) don't preview it wrong, it's impossible to say why a 3rd party app doesn't like it. 

[MJP]

Hi Gabe, and thank you for your reply.

The issue is unlikely to be down to the RIP, I would have thought, as this is a very expensive professional RIP which is running a recent version of the Adobe PDF Print Engine (APPE 4.4) that postdates my version of Acrobat 10 by some years. In any case, if the colour values of the linked graphics in the PDF exported from Publisher are identical, why would the RIP print them differently from those generated directly in Publisher?

The issue is the same if I link the original .afdesign file to Publisher rather than exporting an intermediate PDF for linking, from which I conclude that it is not specifically a problem with the Designer PDF export process or settings.

If the composite Publisher image is flattened/rasterised before exporting to PDF, it prints correctly. The PDF exported from Designer with the 'DESIGNER' text in the example also prints correctly independently in the RIP; only when it is linked to the Publisher document do the colours shift. Everything appears to point to the handling of the linked files within Publisher.

For what it's worth, I regenerated the original document using the identical workflow in Adobe Illustrator and InDesign CS6, and that behaved and printed as expected.

I have attached the composite Publisher PDF herewith in case that might be useful for further diagnosis.

I shall raise a support ticket with the RIP manufacturer to see if they can shed any further light, but would be grateful meanwhile for any further insights or suggestions.

Many thanks.

 

Publisher PDF Export.pdf

[Gabe]

Ah, your PDF actually helped me figure out what was going on. You can actually replicate the text mismatch colour in Acrobat, if you simulate a different colour profile. Thing is, you would not see it until do this.

It looks like when we export text, we don't tag it with an ICC profile, but leave the default "Device RGB". In my tests, I was not embedding ICC profiles so I could not replicate it. One workaround is to untick "Embed ICC" and that should give you the correct result. Alternatively, work in the ICC you're actually printing. It would be no advantage in working in ProPhoto, if your end result is printed say in Forga27. 

I'll check with our developers to see why text is not ICC tagged.

[MJP]

Thank you for your further very helpful feedback.

I take your point about there being no advantage to working in ProPhoto in this instance; however, I use ProPhoto as a default working space as my primary business is the reproduction of artwork in the form of limited edition prints for artists, where the maximum gamut and colour accuracy is required. The RIP takes care of the conversions to the appropriate printer/media profile, which in this case is RGB, not Fogra27 or any of the CMYK profiles, and is set to use embedded profiles in PDF source files.

I am not certain it is merely text that is not being ICC tagged, if that is the cause, as the original document (a Covid precautions poster) that first showed the issue had identical symptoms with linked Designer graphics including a partial fill and an outline ('picture frame'). I can upload one of these graphics as a further example if that might help; the previous file was just a simplified synthetic test image to illustrate and explore the issue while investigating alternative settings and options.

My entire workflow is fully colour managed and normally 'just works', with highly accurate print output, so it has been something of a struggle to narrow down the possible cause(s) of this particular issue.

Hope the above might be of some further help in progressing this, but do please let me know if you need any further detail in the form of program settings or additional sample files etc.

[Gabe]

Oh yeah, it makes sense then. It could be that other objects failed to get the correct ICC tag. If you don't mind, could you upload some other examples that you know for sure are affected by this? You can use this private link : https://www.dropbox.com/request/mNUQmMfXsYxArBZPdUXY

[MJP]

Additional files uploaded to your private link as requested.

Further subsequent testing on these uploaded files indicates that, if the RIP is set to default explicitly to ProPhoto as the input profile rather than relying on any embedded profiles, the colours are then broadly as expected, i.e. comparable to the original Publisher document and with no difference between the linked Designer graphics and those generated within Publisher**.

It seems clear that the linked graphics are losing their ICC tag somewhere in the export process; that is, assuming they were correctly tagged in the first place.

**There appears to be a very minor visual difference in the RIP preview if 'use embedded profiles' is left on along with the change of the default input profile to ProPhoto; this vanishes entirely if 'use embedded profiles' is switched off. I can't currently account for this small discrepancy, unless again it is connected to the ICC tags, or lack thereof.

 

[Gabe]

Thanks. Issue now logged