Linearizing a press (was Re: Max K generation question)
Linearizing a press (was Re: Max K generation question)
- Subject: Linearizing a press (was Re: Max K generation question)
- From: Terry Wyse <email@hidden>
- Date: Mon, 27 Sep 2004 15:45:54 -0400
Hi Roger,
Depends on what you mean by "linearizing". If you mean make a 50% dot
on plate measure as a 50% dot on paper, then, no, you'd probably NOT
want to do this. A press (and the separations/CMYK recipes being fed to
it) is expected to have a certain amount of dot gain/TVI (Tone Value
Increase). "Normal" TVI is anywhere from about 15% to 25% depending on
what you're targeting. I think if you attempt to linearize a press from
a dot% standpoint, you're profiling package will probably have a hard
time dealing with it as the spacing of the values on a step wedge will
be sort of whacked from a colorimetric standpoint. As an experiment,
try linearizing and profiling an inkjet printer in the same manner and
you'll see what I mean! You'll probably end up with very abrupt
transitions in the shadows.
I prefer the term "press optimization" where you measure the press's
current state using linear plates and then adjust the plate curves to
achieve a specific TVI (GRACoL/SWOP/whatver). This is the standard
process I go through in setting up a press prior to profiling it.
Now, if you're talking about linearizing a press using something other
than dot gain/TVI as a measure, then I'm all ears! I've had some ideas
in this area that I'd like to try but that I'm not ready to divulge
publicly.
Cheers,
Terry
On Sep 27, 2004, at 8:45 AM, Roger Breton wrote:
Has anyone ever attempted to "linearize" a printing press, prior to
profiling?
How do you mean, Roger?
Rich Apollo
I mean find screen percentages input values that will yield a linear,
progressive (monotonic?), Tone Value Increase on the press. Sort of
when you
take a look at dot gain curves on a well linearized inkjet printer. I
hear
some folks in Europe go through this exercice before they try to
profile a
press.
How that is done, in actual practice must not be for the faint of
heart as
it requires some iterations. I hear it's easily done on a QuickMaster
DI.
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Color Management Consulting
email@hidden
704.843.0858
http://www.colormanagementgroup.com
http://www.wyseconsul.com (coming soon)
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