Digital Prints

it is not. In the context of color management, calibration means changing the printer’s
behavior to bring it into a predictable state where ink densities and tonal values are known
and stable. In order to get accurate color and to take advantage of color management (and
to make the profiles I’ll be describing next), a printer has to be consistent in its output,
and calibration forces it to be that.
While many high-end digital printers (usually working in conjunction with equally highend
RIPs) offer printer calibration with the use of on-board densitometers or spectrophotometers,
many inkjets do not have a built-in form of calibration. Notable exceptions are
the more commercial, large-format printers from ColorSpan, Encad, and HP.
One of the few desktop inkjets to offer this function is the HP Designjet 30/130 inkjet
printer, which has its own automatic, closed-loop color calibration procedure. What happens
first is that a test pattern is output by the printer. After allowing the ink to dry for a
short time, the printed page is fed back into the printer and analyzed automatically by a
built-in optical sensor. The sensor measures the different color patches, and correction
curves are created that will then alter the output of the printer and bring it back to its predetermined
base point.
Another way to calibrate
a printer is by using a
RIP that provides this
calibration function in
conjunction with a measuring
device. Two popular
such RIPs geared to
photographer-artists are
StudioPrint (by ErgoSoft,
PC only) and ImagePrint
(by ColorByte), and both
have calibration features
(see “Linearization” box).
(For more about RIPs,
see Chapter 11.)
A final thing to do with
any printer that cannot
be calibrated is simply to
re-profile it if colors start
to drift or look wrong. This is what Epson suggests for its desktops, even for the higherend
Stylus Pro 4000 (the larger-format 7600, 9600, and 10600 use optional RIPs that can
be calibrated or the Epson Color Calibrator).
Is not being able to calibrate a printer a major issue? It depends on your tolerance for variability.
It’s more important for printers that are used for proofing and press emulation
where there’s no room for color error. For normal bitmap-image printing with inkjets, it
may not be as vital, but it’s still desirable.
Chapter 4 ■ Understanding and Managing Color 133
The HP Designjet 30/130 is one of the
only desktop inkjets with built-in color
calibration. Note how the process
calibrates for a specific paper type and
print quality.