[cairo] Spot colors (and CMYK)

[Chris Murphy]

On Feb 20, 2010, at 6:31 PM, ecir hana wrote:

> On Sun, Feb 21, 2010 at 1:48 AM, Chris Murphy <lists at colorremedies.com> wrote:
>> 
>> On Feb 20, 2010, at 2:04 PM, ecir hana wrote:
>> 
>>> LAB fallback = tagged CMYK fallback, that's what I said.
>> 
>> Not the same thing, at all.
> 
> Why not? Because of smaller gamut? I thought a profile could map the
> highest alternative CMYK values to your LAB values.

Many spot colors have no CMYK equivalent that ensures reversibility back into its original XYZ/LAB value.


> 
>> PDF/X-1a has limitations - when I referenced it, I'm referring to it as a broad concept. One area where it fails is that spot colors can be defined with CMYK alternates, which is absurd and useless. If it were up to me, it would be mandatory to tag them with an XYZ or LAB value.
> 
> What's useless about having a spot alternative defined in CMYK? I
> thought it's great - if the spot is unavailable you could still easily
> print it. It also helps with blending (as in multiply).

You might as well print it with hatch marks because it has no correlation whatever with the original color.


Chris Murphy
Color Remedies (TM)
New York, NY
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Co-author "Real World Color Management, 2nd Ed"