Re: Inkjet profiling ABC
Re: Inkjet profiling ABC
- Subject: Re: Inkjet profiling ABC
- From: Henrik Holmegaard <email@hidden>
- Date: Wed, 14 Nov 2001 07:56:11 +0100
joseph <email@hidden> wrote:
I do not use a RIP or profiler that allows for manual adjustments of
ink limits or black generation for inkjet printing. My lack of
experience with this has me wondering where the control of ink limits
and black generation is "most" beneficial - in the profiling software
or in the RIP software or both?
First make sure the device forms color optimally. Linearize the RIP
to make sure the full tonal range is used.
Then build a profile for that inking behaviour, that ink set and that paper.
Not all ICC print profiling software supports black generation
settings explicitly. Eye-One Match supports wizards with implicit
presets. ProfileMaker Pro supports presets and explicit override
commands.
If your printing system is not stable, and there is no calibration
capability for it , then and only then should you use the ability to
linearize the profile. This you can do in ProfileMaker Pro, but not
in Eye-One Match.
Do not linearize first the RIP and then profile - and if you are
using iQueue then also apply linearizing here. Choose only ONE place
to linearize, preferably in the RIP software (for the reason given
below). This caveat you will find in the iQueue manual.
Some inkjet RIPs have built-in linearization and calibration and
others do not. With linearization presets all you have to do is find
one that matches the paper and ink set you are using, print the test
chart, allow for drydown, and create your profile. With manual
linearization you have to create the curves yourself. You should see
proper differentiation in the dark patches when things work right.
I posted an inkjet profiling ABC some time ago. The long and short of
that story is that if your RIP controls the total ink coverage, then
your profile should be set to 400% CMYK (: all of what the RIP gives
you in the test chart print). If the RIP does not control the total
ink coverage, then you just have to print the test chart without ink
limiting causing reduced patch differentiation, and then create a
profile for that test chart where the profile imposes an ink limit of
210 - 280 % depending on the paper. You should of course not apply
the ink limiting in an ICC profile of any kind to the test chart you
are printing, nor should you apply ink limiting to the test chart
through in-RIP emulation modes which apply the ink limiting in a
PostScript 'profile' to the CMYK values.
The black generation is how black replaces the other inks in
different areas of the color space. For inkjets you should restrict
black replacement to the shadows and darker tones. Black dots cause
peppercorns which affect the visual quality of your screening. A
smart profiling application will preset all this for you
automatically.
Hope this helps