Digital Prints

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Mastering Digital Printing
Similarly, wide-format Epson Stylus Pros (including the 4000) have proprietary auto head
alignment and nozzle-check technology. A built-in light-beam sensor precisely aligns and
checks all color channels automatically, and it also reads the nozzle-check pattern and automatically
cleans the printhead if any problems are found—even partially clogged nozzles.
The ColorSpan X-12 also has an image sensor that supports automatic features like analyzing
and aligning the 12 printheads, eliminating banding by mapping out the sub-par nozzles,
and providing color density data to external RIPs for linearization. Another separate
sensor helps read color patches and ties into a color management system for color profiling.
And finally, as I already mentioned in Chapter 4, a few wide-formats, including the
HP Designjet 5500 and 30/130, include an automatic closed-loop, built-in sensor color
calibration process.
RIPs
As I explain elsewhere, you may not need a raster image processor (RIP). RIPs can cost as
much or more than the printer itself, so weigh this carefully. In general, if you’re primarily
printing single, RGB bitmapped images without PostScript elements, and you’re planning
to use a desktop inkjet, an optional RIP is not a requirement. If, however, you want to wring
the last 10 percent out of the image, a good RIP can help. For example, most RIPs can control
very precisely how and where the inks are laid down. Of course, the built-in printer
drivers do this, too, but it becomes more important if you use third-party inks and/or nonrecommended
papers that the printer wasn’t designed for. Setting precise ink limits, defining
at what points the light magenta and light cyans come into the image, mixing differing
amounts of black with the other colors for dense shadows or “rich blacks”—these are the
kinds of things RIPs can sometimes do better than the installed printer driver.
The Canon imagePROGRAF W6200
comes with a built-in Canon Graphic
(PostScript) RIP.
Courtesy of Canon USA, Inc.