Re: Ink Restriction (Terry Wyse)
Re: Ink Restriction (Terry Wyse)
- Subject: Re: Ink Restriction (Terry Wyse)
- From: Jouni Mustonen <email@hidden>
- Date: Wed, 22 Dec 2004 21:23:25 +0200
Title: Re: Ink Restriction (Terry Wyse)
Hi all,
Thanks Terry for good advice.
Only thing I am missing is a piece of software that would show a graph of Lch values measured with a device (in my case GMB i1).
I know you can use GMB Measure Tool to make text files from readings and massage the information in spreadshee to get some soft of graph, but Im too lazy do that each time I need to make ink restrictions.
Any free/commercial utils available? I my case Windows apps version is more interesting.
Regards,
Jouni
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
#######################################################
Tämä viesti on virustarkistettu. Virustentorjuntajärjestelmän tietokanta päivitetään
säännöllisesti tartuntariskin minimoimiseksi. Huomaa, että täyttä varmuutta
tiedostojen puhtaudesta ei ole.
This message has been scanned for virus infections. Virus definition database is
updated regulary to minimize risk of infection. Please note that there is no absolute
guarantee that files are clean.
#######################################################
_______________________________________________
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