Re: PDF X4 workflow and CM
Re: PDF X4 workflow and CM
- Subject: Re: PDF X4 workflow and CM
- From: Dan Wilson <email@hidden>
- Date: Wed, 11 Aug 2010 16:13:23 +0100
- Thread-topic: PDF X4 workflow and CM
Hi Paul,
Thanks for the very interesting question and thanks Olaf for your response.
Paul, were you able to identify where the inconsistency was introduced?
Best regards,
Dan Wilson
On 27/07/2010 20:02, "email@hidden"
<email@hidden> wrote:
> Today's Topics:
>
> 1. PDF X4 workflow and CM (Paul Sherfield)
> 2. Re: PDF X4 workflow and CM (Olaf Dr?mmer)
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Tue, 27 Jul 2010 11:28:31 +0100
> From: Paul Sherfield <email@hidden>
> Subject: PDF X4 workflow and CM
> To: "email@hidden"
> <email@hidden>
> Message-ID: <C874735F.6BD2%email@hidden>
> Content-Type: text/plain; charset="US-ASCII"
>
> Hi
>
> I am running some 'real world tests' on PDF X4 files for the UK
> DigitalAdLab. We have prepared 12 'test' ads with differing colour spaces
> and profiles for raster and vector files, and using ISO coated v2 300ECI as
> the output intent.
>
> To test what we believe the ad clients will need, common colour appearance
> from all suppliers if PDF X4 is to be used, we are processing these files
> though a number of vendors CtP/colour server workflows.
>
> First results are interesting, not withstanding differing CMM's, vendor
> specific RI's ect., if the CM settings are common to the systems a similar
> result can be obtained for images and vector files.
>
> But, and this is a big but, text and tints in RGB. The master files were
> prepared in Indesign CS4 which has a document colour setting for RGB and
> CMYK, however, as far as I can see this is not 'embedded' in any way. So the
> workflow uses the RGB default profile for these files.
>
> In practice this does cause the CMYK colour breakdown of RGB text and tints
> to change according to the Indesign document profile and workflow default
> profile match or mismatch.
>
> Am I missing a trick here, or is this an area where there is a gap in
> document CM in this workflow?
>
> Comments please.
>
> Paul Sherfield
>
>
>
> The Missing Horse Consultancy Ltd
>
> Telephone: 01442 871752
> Mobile: 07899 906385
> http://www.missinghorsecons.co.uk
>
> Apple Solutions Expert-Print & Publishing
> Member - UK TC130 Technical Advisory Group (ISO 12647 Printing Standards)
> Member - BPIF Technical Standards Committee
>
> ------------------------------
>
> Message: 2
> Date: Tue, 27 Jul 2010 15:12:18 +0200
> From: Olaf Dr?mmer <email@hidden>
> Subject: Re: PDF X4 workflow and CM
> To: ColorSync <email@hidden>
> Cc: Paul Sherfield <email@hidden>
> Message-ID: <email@hidden>
> Content-Type: text/plain; charset=us-ascii
>
> Hi Paul,
>
> by definition, a PDF/X-4 file comes with an OutputIntent for the intended
> printing condition (you mention ISO coated v2 300% as the profile you have
> been using as the destination profile in the OutputIntent).
>
> For any page object in such a PDF/X-4 file, notably including any (ICC based)
> RGB vector or text objects, when making plates / doing the print run, those
> objects have to be converted to the destination profile in the OutputIntent
> (here: ISO coated v2 300%), taking into account the rendering intent set for
> each object in the PDF file. The result of such conversion should be
> equivalent across CMMs and workflow systems.
>
> If the result is not consistent, any of the following aspects may have been
> carried out incorrectly (list not complete!):
> - converted to some other CMYK profile (not the one in the OutputIntent; note
> that other profiles produce other separations, even for the same printing
> condition...)
> - ignored the source RGB profile(s) and used some other RGB profile
> - rendering intent overridden (ignoring the rendering intent specified in the
> document for each object)
> - some "optimization" or "fixing" or "normalizing" was applied to the PDF
> before or after color conversion
> - the file was flattened to a non-transparent representation before color
> conversion
> - ...
>
> Hope this at least offers some ideas of why there might be variation in the
> real world.
>
> Olaf
>
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Colorsync-users mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden