Re: Maximizing printed gamut
Re: Maximizing printed gamut
- Subject: Re: Maximizing printed gamut
- From: Roberto Michelena <email@hidden>
- Date: Tue, 12 Mar 2002 13:17:49 -0500
>
1) How do you determine the maximum gamut of a press?
<snip>
>
We've just completed a series of press runs to test the difference various
>
printing conditions make on the gamut of the printed sheet. I am disappointed
>
by the limited differences realized.
<snip>
>
Is there profile/gamut comparison software already available? From whom?
>
(Stand-alone app. would be preferred.)
As Henrik already stated, there's a gamut for a "press and its condition",
not for a press.
For each running condition (ie TR001, Gracol, ISO 12647-2, and your own) you
want to evaluate, you run a test to those specs. You include in that press
sheet a target, ideally something you could make a profile of, such as
PrintOpen's standard or an IT8.
Then you measure the target (ideally measure a few and average) for each
condition, and either:
- use a graphing software that can plot gamut without making a profile
(ColorThink, ICCTools are two that come to mind)
- make a profile and use software that can compare profile gamuts (many of
them).
I believe ColorSynergy's Gamut Viewer is still the best. ColorThink's is
great too, but not as good as ColorSynergy's. PrintOpen's sucks (IMHO). I am
not familiar with ProfileMaker's viewing tool. Monaco's is just a tad better
than PrintOpen's, fairly insufficient.
Now, all this only makes sense if you want to include your own "house
flavor" or other non-standard specs in your comparison. Otherwise, you would
just get hold of existing TR001 and ISO (Fogra) profiles, and Gracol (are
they available?) ones, and run your comparison on those.
If you want to generate a "house flavor" with the largest possible gamut,
that's another story. A long story, since first thing to look for would be
materials, such special inks that are cleaner and with heavier pigment load,
better papers, reverse-osmosis water, etc etc.
Once set in the materials, you would run tests at different densities for
each ink, stopping when printing becomes unstable (ie ink/water balance).
You measure each test, and graphing them you'll find that at some point an
increase in density doesn't bring any more saturation. That's the "maximum
gamut" density for that color. Don't worry about dot gain, since nowadays a
good rip and CTP can compensate with a steep curve without loss.
But you don't set on those "max chroma densities" inmediatly, you have to be
sure there are no trapping problems and also check the saturation of your
secondary colors. And the total ink limit to be viable, if your max
densities are great but limit you to 180% total ink and give you trapping
problems if you go over that, then they are not good.
In all, a long and winded process that only a few specialty printers seem to
be willing to endure.
-- Roberto Michelena
EOS S.A.
Lima, Peru
_______________________________________________
colorsync-users mailing list | email@hidden
Help/Unsubscribe/Archives:
http://www.lists.apple.com/mailman/listinfo/colorsync-users
Do not post admin requests to the list. They will be ignored.