Graphics Programs Reference
In-Depth Information
color space. When printing out of Photoshop, it's important that the
Print
with Preview
dialog show the document as untagged and the Print Space
is set for
Same as Source (No Color Management
in CS2). This ensures the
data is not color managed by Photoshop. In Chapter 9, see Tutorial #9,
“Print with Preview.”
If printing from a RIP or other print driver, it is equally important that
no color management be applied to the target data. The settings used to
pass the target data to the printer must be recorded since the same set-
tings will need to be used once the profile is built. I like to make screen
captures and save them to disk with the name of the printer and media
settings. Later, if something changes in your color management pipeline,
having these screen captures helps to identify if the problem was an
incorrect print driver setting. Having profile targets printed remotely
requires good communications with the shop producing the output. It's
critical that the shop output the target exactly as they will print the final
job. If you are profiling a press or a printer that uses a specific paper stock,
the conditions must be the same for the target as for the eventual job.
This means using the same papers and press conditions. Many shops do
not inspect the files for output, or alter the documents without being
asked to do so, which is good. If you are profiling a remote printing device
and suspect that a user on that end might open or worse, manipulate the
file, a conversation is in order as it is critical that the target be output
“as is.”
If you are printing a target, it is absolutely critical that whatever
process is used, you ensure that the color stabilizes or dries down prior
to measuring. For example, some ink-jet printers use dye-based inks that
will not fully dry down and become color stable for at least 24 hours, and
sometimes longer. Others, notably pigmented inks, dry down far faster,
sometimes within minutes. Since not all the inks may equally dry the
same, even 95 percent stability isn't good enough. Obviously, the printed
targets should be handled with care. Smudges or fingerprints on a single
color patch could result in a poor reading and the resulting profile will
suffer. This is another reason why Spectrophotometers that measure
multiple readings per patch are preferable. Spectrophotometers such as
the PULSE, Eye-One Pro or Spectrocam, which require the user to slide
a sensor over the print, could touch the surface and scratch the print.
This should be avoided at all costs. Often you can lift the rear feet of the
Spectrophotometer off the paper surface slightly to make sliding the unit
easier. Do not let the unit or the ruler that sits on the print scratch the
surface as the ruler is moved from row to row. Often rotating the print
being measured 180 degrees half-way through the measuring process
makes it easier to ensure the unit doesn't scratch the print surface. It is
also a very good idea to place several sheets of the same paper you are
measuring under the target. This backing will ensure that the data meas-
ured isn't influenced by whatever colored surface the target might be
sitting upon.
