Graphics Programs Reference
In-Depth Information
under a D50 balanced light box. The client either accepts the colors of
the proof or not, in which case another round of corrections and addi-
tional contract proofs are generated (usually at their expense). Once the
client accepts the contract proof, they sign off on the actual proofs and
go home. The files and the contract proof end up at the print shop.
The pressman (he or she is the person running the press) does what-
ever necessary to get the press running as it should. This sometimes is
called
getting the press up to density
. The press is running to some shop-
desired specification (or it should be). The pressman runs the job and
compares the press sheet to the contract proof. The two need to match
closely. When they do, the art buyer gets a call at 2
A
.
M
. and runs down
to the print facility to examine the press sheet and the contract proof,
once again under the light box. The client signs off on the press sheet,
indicating that it and the contract proof match to their satisfaction. Even-
tually the press prints the entire print job and the client comes back to
pay the bill and pick up the job. Ideally, the press run, the contract proof,
and signed press sheet still match.
Many users have heard the term
Matchprint
and assume that this is
the sole proofing system I have been calling a contract proof. Just as you
can blow your nose in all kind of products other than Kleenex, you can
produce contract proofs on all kinds of products other than Matchprint.
Kleenex and Matchprint are two specific brand names of products. As
for contract proofs, there are many kinds, such as
Fuji ColorArt
,
Kodak
Approval
,
DuPont Cromalin
or
Chromalin
,
DuPont Waterproof
,
AGFA Press-
match
, and of course, the well known
Matchprint
(a product now owned
by Eastman Kodak).
Besides all these different contract proofing systems, there are a
number of different substrates available for many uses on these contract
proofing systems. For example, in Fig. 7-1 I have measured the ECI2002
target printed on three Matchprint proofs all from the same device but
having three different substrates: Commercial, Publication, and Super-
White. As you can see, a Matchprint isn't simply a Matchprint. Notice
the differences in the average deltaE of the two most similar stocks (Com-
mercial versus Publication). Now for a reality check: Fig. 7-2 shows the
average deltaE between the same Matchprint contract proof from two
different vendors. Which is correct? Since I measured and built a profile
from each contract proof, the correct profile is obvious. What would I do
if I didn't have a custom profile?
Since the contract proof is one item that both the print buyer and
printmaker agree to match, it is critical that the conversion to CMYK be
optimized for this process whenever possible. It is possible to profile the
actual press the job will be printed on, but there are issues surrounding
this task. The aim is to produce a contract proof that is close to an ideal
condition whereby a pressman can match his or her press to this proof.
Our job isn't to take away the necessary skills of the pressman but rather,
to provide a file that allows the pressman to produce a very close match
