Hi Roberto,
You are right, many times the black ink is not neutral (inkjet, offset, etc.) If the ICC profiler does not take care of it, gray balance is not properly acheived and very often, users start to do tweaking to the profile, trying to fix it. But this is not always the way to fix the problem.
Raw equal RGB (CMY) values printed with utrachrome inks, via Epson driver, with "No color adjustment" renders a very greenish tone scale (white to black), and the black ink is somewhat brown/red. This is, like you said, good profiling package have to deal very well with such "non-graybalanced" state.
Since our first realease (now version 3.6) or PerfX Color Managementâ„¢, we take care of such issue related to non-neutral black ink. Gray balance is allways acheived by checking the black ink neutrality first. This make our ICC profiles to render very good gray balance. Many users and testers had reported it to us.
_________ I guess it's unlikely, unless the black ink is very non-neutral. A good profiling package deals with non-graybalanced states, and even with crossovers (in which the equal CMY points cross over the neutral axis from one hue to another). But if the black ink is very non-neutral (and still dark), one of the spikes you're looking at could be 100%K and the other the true composite black point...
So is this RGB profiling (via driver), or CMYK (via RIP or some sophisticated driver)?
-- Roberto Michelena _________
Louis Dery v.p. Nouvelles Technologies / New Technologies TGLC inc. www.tglc.com email@hidden 418-877-9114
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