Re: 100% GCR with UCA?
Re: 100% GCR with UCA?
- Subject: Re: 100% GCR with UCA?
- From: "Stuart Peel" <email@hidden>
- Date: Wed, 22 Oct 2003 04:22:45 -0700
- Priority: normal
- Thread-topic: 100% GCR with UCA?
Hi David,
Thanks for spending some time on this. It's getting very difficult for
me to completely understand exactly how to acheive what I need so, I
decided to speak a thousand words with a picture! Sorry that the rest of
the group can't see this, but attachments don't carry through to this
list. Anyone interested, drop me a line and I'll send a copy.
For a description in text, this is what I think David is suggesting:
100% GCR setting, Black generation starting at zero at 45 degree angle
upto the point where colour is required to enrich the black. At that
point, dip the black to add colour.
I have added some coments in the body of the text below, which starts
with .......etc.
<-----Original Message----->
From: email@hidden
Sent: 10/21/2003 1:28:59 PM
To: email@hidden;email@hidden;email@hidden
Subject: Re: 100% GCR with UCA?
If your goal is for all gray component to be rendered to the black
channel, then the setting you need is "maximum" for black generation;
which would indeed be a zero toe, and a 45 degree ramp from there. This
will seperate all balanced gray components to the black channel. It
sounds like you are actually trying to do the opposite of the usual.
Typically black is excluded at the light end, and used exclusively at
the dark end.
.......Absolutely correct, especially in proofers and inkjets that put
down that unwanted black dot in the highlights and 1/4 tones. However,
this is a news printing environment and the objective is to save ink
(CMY) but retain richness in the shadow end.
You appear to want black only at the light end, with color mixed back in
at the dark end, ending with a rich black.
......Not only at the light end. Please see the attached picture that I
put together in PowerPoint.
If you start with the with the maximum BG setting, and add in about 20
or 30 percent UCA the lower half of your ramp will remain all black,
before the color starts being added back in. If that starts adding color
too soon, set UCA back to zero, and try nailing the first three
quarters of the BG ramp with control points to keep it steady, then
adding a couple control points in the dark end to judiciously add a dip
in the ramp down from the upper right corner. This will leave all
neutral components in the black channel up until the point of your dip
in the ramp, where CMY will start getting added back in. Remember that
total ink does not guarantee that amount, it simply provides assurances
that you won't get more than that amount, in other words its a cutoff.
.........I think I get the drift!
Thanks again.
Kind regards,
Stuart Peel
[demime 0.98b removed an attachment of type application/octet-stream which had a name of GCR_UCA.ppt]
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