Building Printer/Output Profiles - Color Management for Photographers - page 185

CHAPTER 6

Building Printer/Output Profiles

Now we get to the nitty-gritty, the nuts and bolts, the main event; build-
ing ICC printer/output profiles. Producing profiles for printers is proba-
bly the most complex of all profiling processes but one that ultimately
provides great satisfaction. Unless the final computer image is to appear
only on-screen, we have to output the numbers in our files to a printer
to view the final image. There are an enormous number of different
printers and printer technologies existing today. The same printer may
be driven by a number of different print drivers or RIPs , which alone
can play a profound role in the color appearance and quality of the final
print. Some printers allow the use of multiple substrates (a fancy name
for papers) as well as different inks or other materials to create a color
image. Some printers have a relatively small color gamut whereas others
have a relatively large color gamut. Some printers require the data
for output to be in an RGB color space; others require a CMYK color
space. Often the same image will need to be printed to a multitude
of output devices, all having many different behaviors. Ultimately
we want the color appearance we see on our calibrated and profiled
displays to be the color appearance we reproduce in print. The key to
producing this goal is the use of ICC profiles. Did you think I'd suggest
anything else?
Before getting into the specifics of how to build ICC profiles for
printers, the different types of instruments necessary, and the options
available in our profile building software, let's look at printers. There are
printers that we can hook up to our desktop systems costing less than
$100 that can produce superb photo realistic color prints. On the other
end of the scale, there are million-dollar commercial print presses. The
same image may need to be sent to both output devices.
When it comes time to profile a printing device, the first item we need
to consider is which color model, CMYK or RGB, needs to be sent to the
printer. This choice isn't as obvious as you would think. For example,
look at an ink-jet printer. An Epson 2200 has seven different colored inks:
cyan, magenta, yellow, black, light black, light magenta, and light cyan.
We could assume that the correct color model to send to such a printer

Definition
RIP: Raster Image
Processor. A RIP is often a
software product that
accepts vector or
PostScript data, takes this
mathematical
representation of a shape
or element, and creates a
series of dots necessary to
output the shape. A RIP
takes raster data and
produces bitmap data
necessary for output.

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