Stephen, I disagree. CMYK and RGB numbers Is not a color, the numbers always depends on the output (display, printer or press) thats why we need icc-profiles.
Lets say a client have a orange logo that is 40m and 100y the output can differ alot if you don't color manage. IMHO thats what icc profiles are for, to make that orange look the same on differnt output-units.
No surprise, I respectfully disagree with you too Magnus! I also agree in part too. Colour is never simple, it can be case specific and what works for one object in a job does not work for another :]
I agree that without a profile, CMYK values are just that – numbers. In some cases, this is all that they need to be, they don’t require a colorimetric description.
A conversion of a files recipe values is not always required or acceptable.
Not all client expectations or print shop workflows are the same, which is why I feel that it is important for both clients and service providers to be on the same page regarding colour handling:
http://printplanet.com/forums/color-management/34408-can-you-export-file/2#post215602
After all, Adobe recognise this fact and provide InDesign with a mechanism to colour manage RGB elements while ignoring CMYK profiles in linked content. Without this option some InDesign users would just turn CM totally off. The “safe CMYK workflow” option is there for a reason.
Take the following case into consideration:
* An InDesign document may be tagged with a document level ICC profile for “Coated FOGRA 39 (ISO 12647-2:2004)”.
* It may have an image tagged with “coated_FOGRA39_GCR_bas”, which has been purposely separated with the intent to contain heavy GCR as neutral tones/gray balance may be critical for this image.
* InDesign CMYK colour policies set to “preserve embedded profiles”, rather than to “ignore embedded profiles” (safe CMYK workflow).
Result?
The intent to have heavy GCR in a neutral biased image has been lost, the intent has been overridden.
Why?
As the document/output intent is a specific ICC profile named “Coated FOGRA 39 (ISO 12647-2:2004)” and the image has a profile named “coated_FOGRA39_GCR_bas”, the colour policy has dictated that the CMYK file has been re-separated through the ICC PCS, loosing the original CMYK recipe build and K channel.
Now both profiles are targeting the same output condition and are created from the same characterisation data, however the current level of colour management is not smart enough to know this.
Some times we don’t want black or gray to become 4 color separated but thats another issue.
It can be hard to separate this issue from others, when colour management is not smart enough to handle exceptions and users have to jump through hoops to avoid colour management screwing up their work. Don’t get me wrong, CM works and is helpful too, it all depends on the context.
The best would be if Adobe would offer a build in dynamic device link option in the Adobe CMM.
That would be great, however just adding the “faux” preserve black/primaries/promote gray colour conversion options from Acrobat Pro would be a start for vector objects and text. We would need something better for rasters though.
Respectfully,
Stephen Marsh