2 Subjects - Cook Book & Profiles For Flexo
2 Subjects - Cook Book & Profiles For Flexo
- Subject: 2 Subjects - Cook Book & Profiles For Flexo
- From: Bill Whitfield <email@hidden>
- Date: Wed, 20 Feb 2002 17:20:32 -0800
Greetings to All,
Subject 1 - Cook Book - thank you to all involved with this very
informative book. FYI - When I printed the book (I still like to read on
paper over screen) to my Tektronix (it will never be xerox to me) 780
images / screen shots on 25 of the pages came out black. I printed from
Acrobat 5.0 and tried all the settings I could think to try in the print
options box with the same results, including printing straight to the
printer rather through our Color Central server. Was it not meant to be
printed with all pages in color? The one item that failed consistently
was the screen shots. Any tips other than the ones under the Printing the
Eye-One Color Cookbook?
Subject 2 Profiles and press gain - please correct where / when needed.
- I am a flexo printer and have to deal will gains that are different
that offset. I know profiling software "knows not CMYK, only LAB. But
since it reads CMYK tint patches to get LAB values and then a proofing
device then turns those values back to CMYK tints, I will need to talk
about CMYK tint patches to get my thoughts across. Presently we are not
using ICC profiles, (I am in the process of buying a profiling package),
but we do have a compensation curve in our workflow so tints and CMYK
images on film are "pulled back" for our press gain. This compensation
allows us to mimic the 20% midtone gain of an offset press with special
considerations made for the highlight and shadows areas. If I print the
target from a profiling software package my 50% magenta area (watch out,
here comes the dots) will gain to, lets say for this discussion, 90%.
Also for this example lets say that my present compensation curve "pulls
back" all 50% areas to 30%. We know that through testing a 30% tint on
film and plates prints on our presses prints 70%. We now have a 50%
"pulled back" to a 30%; a 30% printing a 70% which give us the 20%
midtone gain we want on press for a 50% area. It seems to me that if I do
not adjust the profile target for my press gain I will have areas that I
want to print 70% actually printing 90% (since 50% prints 90%), the
profile will take the LAB value for the 90% and replace all 50% areas
with that value which would make a proof using that profile look much
darker that I want it to be. If I linearize the press target will the
profile software now "pull back" the 90% area to 50% and then assign LAB
values to that 50% area in which case the proof would look too light
because I actually want 70% values in the 50% area? With my present
education on profiling I would opt to "pull back" the profile target,
print it, make a profile and use that profile for my CMYK proof printing
workflow - right / wrong?
How about the profile for RGB to CMYK conversions. Presently when we have
to do a conversion (far and few between) we use 0% dot gain, UCR with
black limit 80% and TIL300%. It seems to me that neither the profile
built from the "pulled back" target, or the profile built from the not
"pull back" target would work for the conversion since they would both
influence the conversion to create values I do not want. In this case my
guess would be to print a non "pulled back" target, linearize it so 50%
area would be compensated to50% by the profiling software. The profiling
software would assigned the "right" LAB values for a 50% tint area as
defined in my press environment. We would then use this profile for RGB
to CMYK conversions. Wrong / right? I would then send this file through
my present workflow to be "pulled back" for film / plate.
Sorry if my explanations run a little long. I come lengthy dissertations
honestly as when my mother was alive her nickname was windy. Thank you in
advance to anyone who reads this and helps with my confusion.
-Bill Whitfield-
MPI Labels
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