Re: [ECI-EN] RGB and CMYK files in a PDF/X-3:2002 file
17 Mar
2008
17 Mar
'08
5:15 p.m.
Hello Peter, hello list
May be, we both are using different definitions about "device
independent workflows".
For me a device independent workflows based on PDF/X must include:
- predictable and pleasant colormanagement of images and vector graphics
- easy integration printing processes with very different colors for
the primaries (e.g. offset according ISO 12647-2 and gravure printing
according PSR ECI
- Independence of profiling vendors
- defined procedures for the quality control of all color
transformations in the workflow
Neither ECI, ICC, ISO TC 130 or GWG have ever published a guideline and
tested in practice how this could be realized with PDF/3 or PDF/X-4
containing ICCbased objects.
You may be able to use PDF/X-3 or PDF/X-4 in repro inhouse workflows as
an internal color master, if you have the control over the complete
creation of the layout documents, the master PDF/X files and the
profiles for all printing conditions in the workflow. File format
delivered to the printer should then always be PDF/X-1a or CMYKonly
PDF/X-4 (plus Spotcolor if necessary).
If we are talking about controlled color transformations of incoming
PDF/X files at the printer. PDF/X-1a or CMYKonly PDF/X-4 in combination
with devicelink based color servers are today the only available
technology which is able to full fill all the points I described at the
beginning of the mail.
Regards
Jan-Peter
Peter Kleinheider wrote:
Jan-Peter,
having set up quite some device independent workflow's in the past, I
do not agree to your statement.
If you can make sure that BPC is used at the end doing the final color
conversion, than this is a pragmatic workaround.
However I agree, that this can be a pitfall if such a PDF is sent to
an "unknown" site which has BPC turned of (or BPC even not available).
Nevertheless, it works.
--
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For the future, I hope that ISO TC 130 and/or GWG
specify a "CMYKonly
PDF/X-4" version (or GWG recommendation) like PDF/X-1a plus
transparencies.
A "CMYKonly PDF/X-4" recommendation by GWG would have the advantage,
that it could be specified on top of the ISO standard PDF/X-4 without
the need to change the ISO-standard itself. This could be realized in
months instead of years for the ISO procedures...
Being partly responsible for that I can tell you that we were in fact
discussing such a new spec at the last meeting. However, we also have
the demand to allow icc based elements (still disallowing
ICCbasedCMYK) in a PDF. For that PDF/X-4 has already most of the
provisions we need.
It would be great the hear the opinion of other users on this idea?
Best Regards,
Peter Kleinheider
Co-Chair Colormanagement Subcommittee of GWG