RE: Brightner vs laminate
RE: Brightner vs laminate
- Subject: RE: Brightner vs laminate
- From: Hanno Hoffstadt <email@hidden>
- Date: Thu, 16 Nov 2006 18:44:21 +0100
Hi Bob, hi Scott,
there is actually a working group of the ECI looking at the color
shifts due to coating or varnishing of offset prints.
As a first step, it makes sense to measure the final (laminated)
print, to create an ICC profile from that. If you separate with
that profile, you will counteract most of the color shifts,
which is what Scott was saying too.
If I understand you correctly, then your result is not satisfactory
in all colors, especially with matte coating. Partly, this may be
due to the 45/0 geometry and the almost perfect coverage of the
measured patch, blocking diffuse light from the sides
- whereas your eyes see quite a bit of stray light when you look
at the matte coated print. (The match tends to get closer if you
shield the print against light from the sides, doesn't it?)
Some years past, my approach was to add stray light (in XYZ or
spectral space) to all target measurements, then to create a
profile. Adding about 1% did the job for me.
The next step is to measure the unlaminated print first, create a
first profile; then to laminate the same print, measure, create a
second profile. With this pair of profiles, you can consistently
simulate the effect of before/after coating with soft- or hardcopy
proof.
Workflow-wise, you would give the second proof to the print buyer
- this one showing what the final product will look like -,
and the first proof to the pressman, who can adjust ink zones to
match the "before coating" look that is consistent with the approved
"final look" afterwards.
Consistency is the key here, and the final goal of the ECI working
group is to find a way to predict the color changes without actually
having to laminate prints. Then you can take e.g. an ISOcoated.icc
profile (which is for unlaminated, but glossy or matte coated paper)
and create a consistent version for glossy or matte laminated prints.
Please contact me off-list for further details, or if you are
interested in contributing data and/or work. See also
https://www.imaging.org/store/epub.cfm?abstrid=30263
Best regards,
Hanno Hoffstadt
ECI Coating WG
Message: 6
Date: Thu, 16 Nov 2006 00:15:17 -0500
From: "Robert Rock" <email@hidden>
Subject: RE: Brightner vs laminate
To: "'Lily Peloquin'" <email@hidden>,
<email@hidden>
Message-ID: <003301c7093e$43ad6d50$c304a8c0@laptop>
Content-Type: text/plain; charset="us-ascii"
Lily,
I myself have recently done significant work preparing profiles for
laminated printed material. We produce primarily books, so the covers or
jackets are usually laminated. Gloss lamination does not present as much of
a problem as does matte laminated covers. But it does greatly improve the
results for either lamination. I used MonacoProfiler with Xrite DTP70
Autoscan SpectroPhotometer. I've been working on this for several weeks now.
After building the profiles, we went back and press proofed several sample
test images or actual products. You will find that you can get spot on to
most colors. But there are some colors that you just can't nail. We are now
in the process of keeping careful records of which CMYK color combinations
give us the most trouble and hope to come up with a range of colors that we
will advise our clients and designers against using. For example, a nice
rich burgundy will turn towards brown after matte lamination. All the other
colors will look great, except this color. So after making your profile,
keep a close eye on the results for awhile. For the most part, it will
GREATLY improve your reproduction, but there will be some colors that just
won't come, no matter what you do to the profile. If you try to "edit" or
tweak the profile, you end up screwing up other colors that were okay.
Good luck,
Bob Rock
Message: 13
Date: Thu, 16 Nov 2006 10:04:07 -0600
From: Scott Martin <email@hidden>
Subject: Re: Brightner vs laminate
To: Robert Rock <email@hidden>
Cc: email@hidden
Message-ID: <email@hidden>
Content-Type: text/plain; charset="us-ascii"
I myself have recently done significant work preparing profiles for
laminated printed material.
I've been color managing a number of highly eccentric (and highly
challenging) printing process for almost a decade. I have got clients
that print onto wood, glass, metal, silk, one that prints with his
own blood and one that actually laminates inkjet prints with melamine
(think digitally imaged Formica). Measuring and profiling the final,
laminated product is essential.
After building the profiles, we went back and press proofed several
sample
test images or actual products. You will find that you can get spot
on to
most colors. But there are some colors that you just can't
nail. ... For example, a nice
rich burgundy will turn towards brown after matte lamination. All
the other
colors will look great, except this color.
If you measure and profile the final laminated product wouldn't your
proofs simulate that brown color? Less than optimal separation
parameters could effect those darker colors as well but you should
still see the results on the proofs.
Scott Martin
www.on-sight.com
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