Re: Ink limiting on Ultrachrome
Re: Ink limiting on Ultrachrome
- Subject: Re: Ink limiting on Ultrachrome
- From: Dan Reid <email@hidden>
- Date: Sat, 01 Mar 2003 10:21:57 -0700
on 2/27/03 12:15 AM, Thomas Holm / Pixl at email@hidden wrote:
>
I've worked quite a bit with profiling printers with Ultrachrome inks
>
lately, and have discovered problems, similar to the ones described in a
>
recent thread about the profile curving in on itself. Essentially the output
>
becomes unreliable in the shadows (closes down), if the ink isn't limited
>
*enough*.
Ain't that the truth. Yet still others don't believe the gospel. Profiling
does a pretty good job of compensating but that ain't it's job.
>
>
If solid densities for each color are too high the profile just isn't
>
working satisfactorily.
>
>
Now the big question is how do you find the maximum allowable density for
>
each ink?
Depends on how you are printing. If you are using a CMYK workflow and the
RIP provides per channel ink limiting and/or linearization curves then you
are in good shape. If you are in RGB workflow then don't worry about it.
Simply use the measured linearization data and open in Excel to note the
density numbers. If you are a Colorthink jockey load linearization charts as
a color list. ICCtoolBox Pro also supports this option. Both can plot in LAB
to see any hooking in the shadows. Guess-timate restrictions until you don't
get any hooking.
>
>
It is of course possible just to do trial and error profiling and change the
>
linearization in between, and then look at a Hex plot (or spider plot) and
>
see if the ends start to curve in, but it would be great if the sweet spot
>
could be found without having to build half a ton of profiles.
>
>
Essentially, how do you find out at what point the inks start to "curve
>
inwards" before building a profile - anyone?
>
Experience and lots of trial and error. You'll nail it eventually.
--
Dan B. Reid
RENAISSANCE PHOTOGRAPHIC IMAGING
http://www.rpimaging.com | email@hidden
Toll Free: (866) RGB-CMYK
_______________________________________________
colorsync-users mailing list | email@hidden
Help/Unsubscribe/Archives:
http://www.lists.apple.com/mailman/listinfo/colorsync-users
Do not post admin requests to the list. They will be ignored.