Re: Inks for VOP (was Dumb question for european prepress specialists)
Re: Inks for VOP (was Dumb question for european prepress specialists)
- Subject: Re: Inks for VOP (was Dumb question for european prepress specialists)
- From: Henk Gianotten <email@hidden>
- Date: Tue, 29 Nov 2005 02:06:26 +0100
At 16:38 28-11-2005 -0600, Rich Apollo wrote:
You miss my point, Henk. The printer in Miami, being in a warm, humid
climate at sea-level printing on an older press might require an ink
with some different characteristics than the printer in Denver;
Denver being colder, much drier, and a mile above sea-level. Presses
of different vintages made by the same manufacturer on our press
floor display some different behaviors. And that's with the same
chemistry, ink, blankets, plates, paper, climate, et cetera. The
point is that the different inks could conform to ISO-2846-1 and
exhibit some different characteristics when they hit the paper.
GANS lists 13 process ink sets on their web site. They list an
additional 9 black inks. Superior lists 13 different process sets on
their web site. They have 9 other categories of ink listed. Kohl &
Madden has 10 process sets in the "Sheetfed Offset" category. None of
these are "specialty" inks. These are just process sets for sheetfed
presses. Flint-Schmidt lists 12 process sets.
Rich Apollo
Sorry Rich,
I used to be a printer a long time ago.
Perhaps that's the reason I missed your point.
I was not aware that the machines in Florida need other inks than those
used in Denver.
I was under the impression that quality printers had an ideal temperature
and humidity to print on a high-speed 4 color press.
And I know that in less ideal circumstances you have a very high humidity
so it interferes with the water-ink balance.
And some inks are less sensitive for those conditions. So they differ.
I know that 8, 10 and 12 color perfectors need sometimes different inks. I
know that high-speed sheet fed presses such as the Heidelberg XL need high
quality inks to obtain maximum quality.
I know the differences in tack, paper, paper surface, color sequence,
varnish protection etc.
And inks to be used if the substrate and other surface conditions differ.
I am also aware that older presses behave different but I was not aware
that they behave different even (as you describe) with the
same chemistry, ink, blankets, plates, paper, climate, et cetera.
I had the idea that most of those differences (within a certain range) had
to do with register, slur and dot gain. The dot gain difference to be
compensated by plate curve corrections.
That's the reason a lot of printers prefer CTP. The tools to compensate are
far better in control compared to manual plating.
But if ink vendors do have ink sets to compensate far more variables in our
process, I am very interested to learn how they describe these unique
product features.
In a recent survey, some 36 printers with different presses in different
locations used different ink sets to match ISO 12647-2:2004.
Nearly all of them were able to reach the target values.
Nearly all inks matched ISO 2846-1.
They were produced by Sun Chemical and a few other large international vendors.
In the descriptions of the tests, however, I could not find any additional
details how these inks could correct for the different press behaviors, you
described.
I will ask the ink vendors how they would describe those conditions.
And report my findings.
Once again, sorry.
Regards,
Henk
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Colorsync-users mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden