Re: Printing grayscale in CMYK
Re: Printing grayscale in CMYK
- Subject: Re: Printing grayscale in CMYK
- From: Henrik Holmegaard <email@hidden>
- Date: Sat, 23 Jun 2001 09:17:32 +0200
Christopher Lund <email@hidden> wrote:
Should I then make a custom CMYK in Photoshop, using the
Eurostandard coated ink setting, dot gain set to 20%, GCR, black generation
set to heavy, black ink limit to 85% and total ink to 350%??
No, you should do as follows:
a. go to www.fogra.org and download the 8 ISO 12647 IT8.7-3 data sets,
b. determine which paper you will print the book on, presumably
glossy in your case,
c. determine whether the printer uses positive or negative plate,
d. load the IT8.7-3 data set that matches your requirements into your
print profiling application,
(Note: Danish printers use positive plates which means COMMSP1 for
glossy paper, Swedish printers use negative plates which means
COMMSP5. The choice of positive or negative plate leads to different
dot gains, hence you must ask the printer as the first step.)
e. click the 'Offset' preset in your print profiling application and
it will give you a black generation for the highest gamut offset
process, which is what you are asking for (say in PM315 ltGCB 320, in
PO40 a UCR, each profile building application has different black
generation just as it has different perceptual gamut mapping, which
is why FOGRA doesn't offer profiles on its web site).
f. for a four color black profile, use the same data as for the color
profile, but max the black with the max black setting (again just
load and click).
If you use the standard colorimetrically defined data to build your
production profiles, you can proof not only the images and other page
content, but the FOGRA control strip, measure the proofed control
strip, and have a contract proof which both you and the printer know
is in the gamut of standard offset on glossy paper.
(What I'm saying is that the black generation in your printer's
Scitex scanner software is not known, let alone hot pluggable into
Photoshop. 350 max, 85 start is meaningful relative to what that
software does, but maybe not relative to other software. It sounds
like a UCR setting, but using black throughout the color space with
GCR is safer if the press is not well balanced, on a proofer which is
stable UCR is great or a low start and light GCR.)