Graphics Programs Reference
In-Depth Information
in Chapter 3 is used for monitor calibration, and the only Spectropho-
tometer supported for print profiling is the PULSE.
For the creation of RGB profiles, PULSE ColorElite provides a basic 343-
patch target or a 729-patch target. For CMYK output profiles, PULSE Col-
orElite supports a 530- or 917-patch target, and even better, the standard
ECI 2002 1485-patch target. PULSE ColorElite allows a user to build
output profiles based upon four preset illuminants (D50, the default, D65,
Tungsten, or Cool White Fluorescent). When building CMYK output
profiles, PULSE ColorElite provides a number of predefined settings for
different devices like Ink-jet, Newspaper, and Color Laser, and the ability
to specify four black generation settings. For a user who needs control over
specific CMYK parameters such as black generation, total ink limits, and
so forth, a higher end package like MonacoPROFILER is recommended.
Cross Rendering
Time to add another color-geek word to our vocabulary.
Cross rendering
,
sometimes referred to as
cross simulation
, describes the process of making
one print process match another. You would think that after profiling two
printers, we could send a document in an RGB working space to each
and get the same color appearance. Due to differences in color gamut,
the types of inks or materials, the surfaces and color of the papers, and
other factors, this isn't the case, However, we can get much closer to
making print A match print B if we have a profile for both printers and
conduct a three-way conversion.
Let's say I have a profile for a printing press producing SWOP (or
contract proof
producing SWOP). I will be using the U.S. Web Coated
(SWOP) v2 profile to produce that final CMYK data. The first step is to
convert the data from RGB to CMYK for this print condition. I would use
the
Convert to Profile
command and convert from my working space,
Adobe RGB (1998) to this printing condition [U.S. Web Coated (SWOP)
v2]. That was easy. The CMYK document will be sent to the press, but
before doing this and paying for an expensive contract proof, I want to
simulate the color on my Epson desktop printer. I'm happy with the soft
proof seen on my display but I need a print to show to a client and send
with the CMYK file going to the printer. Simply sending an RGB file in
a working space to the Epson, even using an output profile, will produce
a lovely saturated print that has absolutely no bearing on the final CMYK
process. It would be a bad idea to send such a print to the print shop, as
it would lead to unrealistic expectations.
How can the Epson simulate the CMYK process without first inform-
ing our CMS about this CMYK process? Since I have a printer profile for
this Epson printer and a profile for the CMYK process, I can cross-render
the two. To cross-render the CMYK file, again I would use the
Convert to
Profile
command to conduct another conversion from U.S. Web Coated
(SWOP) v2 to the Epson output color space. Alternatively, I could use
Definition
Contract proof:
Name
of a color proof that is
supposed to match a final
print condition, usually a
four-color press sheet. The
proof is contractually
agreed by print buyer and
print producer to match
the final print conditions
on the press. A Kodak
Matchprint is a common
contract proof. Contract
proofs and their role in the
printing process is
discussed in Chapter 7.
