The Vibrant Variable Game
By Mark Vruno -- graphic arts online, 8/1/2006
Color sells, and so does variable-data print. So what better combination than to marry the two, as Hewlett-Packard and Graphic Arts Monthly have done on this month's front cover?
The red-eyed leaf frog image demonstrates the extended gamut of the HP Indigo w3250 web-fed, dual-engine digital press using the IndiChrome color set. With a different copy number on each of the 80,000 printed for a unique promotion, this piece of print is driving traffic to GAM's website, serving as another example of integrated-media marketing. (To see if you've won an HP digital camera/printer combo, go online to www.graphicartsmonthly.com/hpcovercontest.)
HP selected customer Adair Printing www.adairprinting.com, Dexter, MI, to execute the job. Late last year, the 75-year-old company converted its 50,000-sq.ft. office/warehouse space to handle a new digital printing operation. (Adair prints automotive catalogs on three cold-set web presses at an ISO 9001:2000-registered plant in Standish, MI.) For the individual numbering element, the printer indexed the job using HP Indigo's Yours Truly Designer, a variable-data software Mac plug-in.
HP has taken the black magic out of ex-tended color sets with IndiChrome, its six-color process. Compatible with all Indigo models, it's available in on- and off-press versions. For IndiChrome OnPress, orange and violet are loaded with CMYK liquid HP ElectroInks. Tints and halftone images are digitally mixed from these six inks, extending the available printing gamut and accurately matching to a wider variety of spot colors than is possible with four colors alone. IndiChrome digital colors are approved by Pantone, simulating the PMS reference book.
IndiChrome takes hi-fi digital color reproduction to the max, yielding lively reds, vivid purples, deeper blues, stunning oranges and warmer yellows. It achieves increased luminosity of a print's overall tonal range—without changing inks or washing up for special colors.
Adair employed the sixth color upgrade that its Indigo w3250 received this summer. All six stations were required, plus the press demonstrated its flexibility with an extra hit of magenta to eliminate moirés. “The orange is actually printed on the same screen angle as the magenta ink,” says Craig Moeller, the digital specialist who oversaw the cover's production. “So wherever the orange was overlayed, the magenta was subtracted out and printed on another angle.”
Converting the tree-frog image from four colors to six was a transparent process, according to Moeller. “Once it was done, all we had to do was submit it to the RIP,” he notes. The key is working in the RGB color space from the outset. “We obtained the original RGB photo so we didn't lose any important color data,” he says. “When RGB files are converted to CMYK and then brought back [to RGB], some data is stripped out and can't be reproduced.”
The w3250 supports media from 27-lb. text up to 100-lb. cover weight. GAM's cover was run on 80-lb. Utopia II Cover from Arjo Wiggins' subsidiary Appleton Coated, via xpedx. Exteriors were spot UV-coated offline.
The fact that a digital press sustained an 80-hour VDP run is a testament to the maturation of these machines. HP wanted to prove that it could be done colorfully. Of course, throwing in a premium or three never hurts!
