1 p.m.
Still about lamination and ink tones:
Roger Breton writes "There are many techniques to work around this problem."
Thanks for your answer, but could you mention what are this other techniques, thanks.
Then about my question. No one really answered it.
Do you have any experience, is this (increasing of dot gain) just because optical
phenomenon of uneven surface of matt laminate plastic or does laminate glue effects to
ink? Do you use different ICC profile to different lamination techniques and lamination
films?
Best regards
Jyrki Kela
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Today's Topics:
1. Matt Lamination turns skin tone to reddish (Jyrki Kela)
2. Questions about PDF/X standards (Tja?a Ur?i?)
3. Re: Matt Lamination turns skin tone to reddish (Roger)
----------------------------------------------------------------------
Message: 1
Date: Tue, 24 Nov 2009 13:40:39 +0200
From: "Jyrki Kela" <jyrki.kela(a)erweko.fi>
Subject: [ECI-EN] Matt Lamination turns skin tone to reddish
To: <eci-en(a)lists.callassoftware.com>
Message-ID:
<E2EBC8585F5A364690E574727DCB95159DC326(a)ex2srv.hq.erweko.fi>
Content-Type: text/plain; charset="us-ascii"
Dear all
We got a strange effect, when we matt laminated offset printed job.
Colour of skin was normal at printed sheet, but it turns really reddish after lamination.
Different was not small. It had never happened to us before. Usually laminated job turns
to be little bit yellowish, not reddish.
At the first I thought that there was some chemical reaction between magenta ink and glue
of laminate or heating of lamination effect to magenta. But I measured dot gain and
checked what process colour there are at skin tone. Dot gain of laminated sheets was about
5 % higher than unlaminated. At this skin tone there was mainly only magenta and yellow
ink. Result of higher dot gain of both yellow and magenta causes reddish tone, compared to
tone where there are all cmyk inks causes only darker tones.
Do you have any experience, is this just because optical phenomenon of uneven surface of
matt laminate plastic? Does this happen with gloss laminate? How do you deal with it? It
is not easy to assume to what tone lamination will effect strongly. Most of case (99.9 %)
lamination does not change tone so strongly. Then to use special lamination ICC profile to
all laminated job is not possible?
Best Regards
------------------------------------------------
Jyrki Kela
9:57 p.m.
New subject: Matt Lamination turns skin tone to reddish
Dear Jyrki,
sorry for not answering earlier.
It's (usually) not the glue but an optical phenomenon that occurs also
with glossy lamination. The additional dot gain is biggest for single
ink tones (around +10% in quarter- and midtones), but also strong for
magenta on near-solid yellow combinations. The effect becomes less
pronounced with very coarse or very fine screens.
If I unterstood you correctly, your concern is that a lamination ICC
profile is not feasible when the effect is sometimes stronger,
sometimes weaker, in other words, unreliable. My findings are that hue
changes are rather predictable when you compare similar screens (e.g.
round or elliptic dot shape at around 150-180 lpi AM screen). In that
case, ICC profiles with and without lamination work quite well, the
way Roger described it. This is why there is an attempt to work with
"standard" lamination profiles (not yet publicly available, but I can
send beta versions upon request). To be clear: different colors are
affected differently - but in a consistent way.
Would you say that your skin tones come out differently each time
after lamination, even if the unlaminated print and the screening are
the same? I'd like to know about that. Currently I know only about a
difference in the surface of the various matte OPP films (different
amounts of stray light)). Oh, and a protective dispersion varnish on
the print will reduce the subsequent lamination effect by 2-4% (by
causing a small shift in the same direction on its own). However, the
final outcome of not-varnished-then-laminated compared to varnished-
then-laminated is approximately equal (if the pressmen did not attempt
to counteract the small shift of the dispersion varnish, what they
usually do of course when they get a proof as reference).
If you'd like to send the CMYK values of your tested skin
combinations, I could give you some typical CIELAB color shifts (e.g.
of similar test patches).
Regarding other techniques: apart from individual profile pairs, there
are attempts at compensation at the printer during plate-making - but
this does not work well, not even with device link profiles, e.g. due
to gamut issues -, and the said "standard" profiles. But all this
assumes that lamination leads to a predictable change.
Best regards
Hanno Hoffstadt
Am 07.12.2009 um 13:00 schrieb Jyrki Kela:
Still about lamination and ink tones:
Roger Breton writes "There are many techniques to work around this
problem."
Thanks for your answer, but could you mention what are this other
techniques, thanks.
Then about my question. No one really answered it.
Do you have any experience, is this (increasing of dot gain) just
because optical phenomenon of uneven surface of matt laminate
plastic or does laminate glue effects to ink? Do you use different
ICC profile to different lamination techniques and lamination films?
Best regards
Jyrki Kela
> Date: Tue, 24 Nov 2009 19:29:25 -0500
> From: Roger <graxx(a)videotron.ca>
> Subject: Re: [ECI-EN] Matt Lamination turns skin tone to reddish
> To: eci-en(a)lists.callassoftware.com
> Message-ID: <007401ca6d66$5752b3d0$05f81b70$@ca>
> Content-Type: text/plain; charset="iso-8859-1"
>
> Dear Jyrki,
>
> Welcome to the real world of color management.
>
> There are many techniques to work around this problem.
>
> The easiest, in my view, is to profile the press with and without
> the lamination.
>
> Then, proof the job with the lamination applied but give the proof
> without the lamination applied to the press for matching.
>
> Best / Roger Breton
>
>
>
>> De : eci-en-bounces(a)lists.callassoftware.com
>> [mailto:eci-en-bounces@lists.callassoftware.com] De la part de
>> Jyrki Kela Envoy? : 24 novembre 2009 06:41 ? : eci-en(a)lists.callassoftware.com
>> Objet : [ECI-EN] Matt Lamination turns skin tone to reddish
>>
>>
>>
>> Dear all
>>
>>
>>
>> We got a strange effect, when we matt laminated offset printed
>> job. Colour of skin was normal at printed sheet, but it turns
>> really reddish after lamination. Different was not small. It had
>> never happened to us before.
>> Usually laminated job turns to be little bit yellowish, not reddish.
>>
>>
>>
>> At the first I thought that there was some chemical reaction
>> between magenta ink and glue of laminate or heating of lamination
>> effect to magenta. But I measured dot gain and checked what
>> process colour there are at skin tone.
>> Dot gain of laminated sheets was about 5 % higher than
>> unlaminated. At this skin tone there was mainly only magenta and
>> yellow ink. Result of higher dot gain of both yellow and magenta
>> causes reddish tone, compared to tone where there are all cmyk
>> inks causes only darker tones.
>>
>>
>>
>> Do you have any experience, is this just because optical
>> phenomenon of uneven surface of matt laminate plastic? Does this
>> happen with gloss laminate? How do you deal with it? It is not
>> easy to assume to what tone lamination will effect strongly. Most
>> of case (99.9 %) lamination does not change tone so strongly. Then
>> to use special lamination ICC profile to all laminated job is not
>> possible?
>>
>>
>>
>> Best Regards
>>
>> ------------------------------------------------
>>
>> Jyrki Kela
5261
days inactive
5261
days old
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1 comments
2 participants
participants (2)
-
Hanno Hoffstadt -
Jyrki Kela