Re: Ink Restriction
Re: Ink Restriction
- Subject: Re: Ink Restriction
- From: Terry Wyse <email@hidden>
- Date: Tue, 21 Dec 2004 13:39:26 -0500
On Dec 21, 2004, at 12:49 PM, Martin Bischofsberger wrote:
I`m using various Rips with diffrent Inkjet Systems.
Each rip offers a possibility for ink restriction of CMYK Inks.
Some even an etra button for Lc Lm restriction.
But nobody gives an advise, how to find the optimal restriction.
Usually they suggest to do it visual. But you know guys, if two
People look at the same chart, everybody will suggest a different
restriction.
So i`d like to know, how you guys handle ink restriction in your dayly
workflow?
Is there a way to do it objective by a measurement device??
For general purpose proofing and/or photo printing, I would suggest
limiting each ink based on maximum chroma (the "c" in "Lch"). This will
give you maximum amount of pure "color" without getting into the area
where the ink starts shifting in hue angle (hue "hooking"). Depending
on the RIP, I tend to find the dot% value where the chroma peaks and
JUST starts to fall off and then back off from this value about 5%,
that way you've got a bit of headroom when it comes time to
re-linearize. Using max chroma, this sort of gets you the maximum
amount of color gamut with the least amount of ink. If you're strictly
doing proofing, you can usually restrict the inks a bit further to
maybe 3-5 points of chroma above what your press is capable of. Chroma
values of around C=65, M=80, Y=105 is usually about right for
commercial offset proofing. Be aware however that if your RIP is
capable of proofing Pantone colors, you may not want to restrict the
ink this much but instead use the "max chroma" method.
For the black, you can simply find where the density peaks or you can
get a bit more sophisticated and look for the dot% value where the
black ink just starts to "open up" a bit or is not quite solid. If
you've got a densitometer handy that can measure print contrast, find
the step that is the Dmax of the K ink, measure this as the solid, and
then find the lower step that gives you around 3-5% print contrast.
Again, this pulls you down from from the Dmax value just a bit to give
you some headroom later on when you re-lin.
As far as doing "visual" ink restriction, I think it's ridiculous
method to try and use, but that's just me. :-)
Cheers,
Terry
_____________________________
WyseConsul
Color Management Consulting
email@hidden
704.843.0858
http://www.colormanagementgroup.com
http://www.wyseconsul.com (coming soon)
_______________________________________________
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
| References: | |
| | >Ink Restriction (From: "Martin Bischofsberger" <email@hidden>) |