[Printing-architecture] Common Printing Dialog and color management

Chris Murphy lists at colorremedies.com
Fri Feb 25 01:46:27 PST 2011




On Feb 25, 2011, at 2:10 AM, Richard Hughes wrote:

> On 24 February 2011 22:51, Chris Murphy <lists at colorremedies.com> wrote:
>> It is common in prepress (usually due to emotionally unstable reasons) to strip CMYK profiles from images and save them untagged.
> 
> Urgh. Uncool. In this situation, won't the "press" be doing something
> custom with Ghostscript and not just clicking "File->Print, OK" and
> hoping for the best?

Prepress already has a specific press condition in mind by the time they are manipulating files, and so they are producing /DeviceCMYK + spot PDF that they expect a RIP to honor exactly. All color management is assumed to have occurred a long time before this, usually in native application files. So the app does this conversion and produces a press ready PDF that is completely untagged.

There are cases were prepress insists on stripping profiles in CMYK TIFF and JPEG also, and then dropping those into a page layout application. They too have been converted to CMYK for a specific press condition and absolutely positively do not want them getting converted again, so in their rule book the best way to ensure there aren't any additional conversions of CMYK TIFF that might have black only text treatment in them (which become 4 color black text if they are converted, which is instantly a crap print job someone has to eat, usually prepress), or any number of other registration anomalous behaviors, they strip embedded color profiles from documents: TIFFs, JPEG, EPS, PDF, you name it. /DeviceCMYK is the way it's done.

And of course, color on the web is a problem. No tags there at all. Stripped on purpose. And I know very very few readers that honor EXIF metadata which often contains Adobe RGB as the color space for the image. But apps that assume sRGB don't check EXIF and assume these Adobe RGB images are actually sRGB. Bad. EXIF color space is a big missing link for applications.


Chris Murphy


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