Graphics Programs Reference
In-Depth Information
the profile provides no such proprietary or useful information for their
competitors. This is usually an excuse for not having a profile. When told
that a printer is producing SWOP, ask if that means TR001. If you are
told that this is the case, the printer likely knows about this standard and
is indeed producing this on proof or press. Then a CMYK conversion
using the U.S. Web Coated (SWOP) v2 profile is going to work well.
Assuming you need to build a profile for a printing condition, one big
issue with handling CMYK conversions is getting the information neces-
sary from the printer or prepress shop about certain print conditions.
Communication is key and setting up antagonism between the parties
serves no purpose. However, getting some shops to go along with your
needs to color manage their process can be tricky. When asking for
specifics, show that you understand the various processes by using the
correct terminology (that you will learn in this chapter), but provide little
details on what you plan to do.
Working with outside vendors that are not color management savvy
or ICC hostile can be a difficult tightrope to walk. When supplying targets
for output to produce your profiles, try to ensure that the files are output
with no manipulation or alterations. You will need to get specific param-
eters about the press conditions to build the output profile. Finding these
answers can be difficult. I've talked to press mangers who didn't under-
stand a simple question like “what total ink limits do you prefer?” The
person who can answer these questions is usually the scanner operator.
If possible, have a conversation with these knowledgeable technicians.
Often you just have to guess, and although this might seem risky, the
outcome is usually better than you would expect. A well-built custom
profile made with default settings often can produce excellent CMYK
conversions.
Although there are a myriad of settings for producing CMYK output
profiles, we can generate a suite of profiles using different parameters,
output a single test image, and get a good idea how well the profiles
perform. Having a proof (and film if using a film-based printing mode)
will allow the printer to examine the conversion and provide reasonable
feedback. They are unaware of how the conversions and proofs were gen-
erated and usually will examine the separations without bias.
CMYK and Black Generation
CMY is a relatively easy color model to understand. It's when black ink
is added to the mix that this color model can be difficult to grasp. Many
differing numeric combinations of CMY and K can produce a specific
color appearance. This is why CMYK is both complicated yet versatile.
By its very nature, CMYK is an print/output space. What makes CMYK
tricky is something called
black generation
. This is a general term, which
describes how the mix of black with CMY is produced and used in the
print process. In addition, there are other parameters that need to be
