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
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Jyrki Kela
Quality and Technology Manager
Erweko Painotuote Oy
Tel. +358 9 7310 2319
Mobile +358 40 7 357 357