Re: -Dirt- yellows in CMY profiles / long /
Re: -Dirt- yellows in CMY profiles / long /
- Subject: Re: -Dirt- yellows in CMY profiles / long /
- From: "Adriano Von Markendorf" <email@hidden>
- Date: Tue, 22 Oct 2002 10:06:35 -0200
----- Original Message -----
From: "Terry Wyse" <email@hidden>
To: "ColorSync User List" <email@hidden>
Sent: Monday, October 21, 2002 11:41 PM
Subject: Re: -Dirt- yellows in CMY profiles / long /
>
on 10/21/02 8:36 PM, Adriano Von Markendorf wrote:
>
>
> Well, I always get profiles that made pure yellows very "dirt" (a lot of
>
> Cyan/magenta/black mixed), in menor degree, of course, have some "dirt"
in
>
> pure Magentas and Cyan.
>
> I know that is very usual have some mixture in pure inks, but I
wondering if
>
> values like L 80 / a 58 / b -3 ( for 100%Y) are usual too for this
category of
>
> profiles.
>
>
I'm hoping you've got the a/b values swapped or else your Yellow ink is
VERY
>
Magenta!
Yes, in fact I really swap, sorry about!
>
Seriously, it's very typical to get a bit of cyan dirtying up your pure
>
"press" yellows in the inkjet proof. The reason is that inkjet yellows
tend
>
to bend towards red as you lay down more ink whereas a pure press yellow
is
>
actually a bit towards the green, hence the spots of cyan in the yellow on
>
the proof. Cyan and magenta inks have similar but different hue shift
>
problems.
I agree. I know that some dirtying is very normal in this cases. But, just
like the Cyan and Magenta, that has aceptable dirtying, I think that is
excessive in the yellows.
>
The key is using some sort of RIP that allows you to determine
>
individual/per channel ink limits. Without this capability, all bets are
>
off. The (second) key is limiting the pure inkjet inks BEFORE the ink
starts
>
shifting hue too dramatically. For yellow, that MAY mean limiting the ink
to
>
LESS than the press density to achieve good results. I suppose given
enough
>
time one could use a profile editor to fix this but nothing beats getting
it
>
mostly corrected PRIOR to profiling!
Unfortunately I must leave the printers in CMY/RGB (with the original
drivers) mode.
>
As a prepress/print person who USED to live and die by measuring density
>
values and dot area, I'm finding them of less and less value the deeper I
>
get into using ICC profiles for inkjet proofing.
>
>
My $.02 worth,
>
Terry
Did you need a trainee? about $.04 /week ?
I know to clean mice ands screens very well.. :-)
Thank's.
Regards,
Adriano von Markendorf email@hidden
"I-C-Cm vitamin's inside" Rio de Janeiro - Brazil
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