Re: Color management in a CMYK world
Re: Color management in a CMYK world
- Subject: Re: Color management in a CMYK world
- From: Lorenzo Ridolfi <email@hidden>
- Date: Wed, 07 Mar 2007 22:57:57 -0300
Mike,
Thank you!
Mike Adams wrote:
Most folks who are reluctant to switch to RGB aren't reluctant because
they care about what color space the file is in. They're reluctant
because they think that if they start working in RGB, they have to
start thinking in RGB. I've got a fifteen-minute demonstration that I
show guys in this situation, and I've never had anyone after seeing it
want to stick with CMYK. You might point out to them that they can
still use whatever sliders in their applications they want.
What kind of demonstration do you do ? A RGB workflow with soft-proof,
etc ending in a CMYK profile ?
I know that there's no "CMYK working space" and dealing with CMYK to
CMYK conversions is asking for trouble. The question is which CMYK
profile should the print guys use when editing the files? The printer
profile? It seems very odd to me... They receive untagged CMYK files
from their customer (actually, they ASK for untagged CMYK files), so
the customer does the separations.
They run large ink-jet printers (solvent based) driven by Scanvec
Amiable's Photoprint. Any recommendation for building profiles for
these printers ? (which target, number of patches, ink limit, CGR
settings, etc).
You can just about bet that running these types of machines and in
this type of environment and with the clients they're likely to have,
that if they get untagged CMYK, it's going to have been created in
Illustrator or Photoshop and be SWOP (the default for both) unless
they accept Corel Draw files which have their own default CMYK space.
Their input is mostly Corel Draw. Do you know which CMYK color space
Corel uses ? And about the CMYK to CMYK conversion. How do you deal with
it ?
And, it's a good bet that on most media they use, SWOP is going to
have a smaller gamut than their printers, which is probably why
they're reasonably happy and don't want to change. It's hard to chase
colors you can't print that way. Only problem of course is that
they're leaving a lot of machine capability lying on the table.
The right way to do it is to profile at the RIP. Photoprint's
sequence--or Flexi-Signs is and I'm pretty sure Photoprint is the
same--as most RIP's, is: single-channel ink limit; linearization;
multi-channel ink-limit; ICC profile. It's a bad, bad, bad idea to try
to set ink limits anywhere other than in the RIP. My procedure with
all RIP's is to do the three first steps in the RIP, then build and
import a Monaco profile. My experience has been that on these machines
right around a thousand patches is a good bet. Fewer gets you a poor
profile and more tends to be overkill.
Thank you. I'll follow your workflow.
Ink limits of course will vary greatly from machine to machine and
media to media. And personally I favor a very light touch on GCR on
all inkjets. What they need with these machines is a profile for every
media they use on each machine, in every resolution they print on that
media. Since most such companies don't know when designing which
machine they might send the job to print to, it's almost impossible to
bind to the correct CMYK space upfront with so many profiles to choose
from.
Ok. In this initial step, I'll only profile the most used paper. It's a
semi-gloss one.
What they need to do is work in RGB, soft-proof to the media they're
going to use through their own machine profiles, then do the CMYK
conversion at the RIP.
I'll be very glad if they start to work in RGB!
Honestly, it's an in-for-a-penny, in-for-a-pound thing. Until they're
ready to do it all, they shouldn't even start.
I know the real results will happen when the full workflow is ready.
Their first objective is have a good soft-proof and a good INTERNAL
color match. I know it's very strange, but the matching with the
customer is the second phase. Of course, showing a complete RGB workflow
is the first thing I'll show after the profile, to try to sell the idea
of a complete workflow.
Best regards,
Lorenzo
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