DIGITAL PROOFING -- Taking Measure of a Proof
In terms of evaluating color, he says the overall issue now is, "What is the target?" Is it an industry defined standard, such as TR001, TR004 or something else. Or, is it a target tailored more specifically to a shop's own color standard.
Pick Your Target
Digital technology has expanded the range of targets that can be used effectively, the consultant notes. That flexibility comes from combining device calibration and color management with the capability to mix colorants enabled by toner and ink-jet systems.
As for how the rules have changed, Zwang reports the study found that color has become less of an issue. "Most of the color proofing vendors have adopted an ICC-based, color-managed workflow within their systems. As a consequence, if you look at the delta errors in IPA's test results, all of the systems did well matching to the targets, especially the known target. They averaged 2.0 to 2.5 delta E variance," he says.
There is a more important issue than color, which is proper processing of the files themselves, Zwang asserts. This is a legacy of the desktop publishing revolution.
"Output expectations now are being set upstream, where the file is created, and are being based on a file processed through a local RIP," Zwang points out. "Therefore, consistency between RIPs in file processing has become critical."
It's an up-hill battle, though. The consultant notes that a recent proofing study ("Proofing: The Customer Is Always Right") conducted by TrendWatch Graphic Arts found that almost 50 percent of the companies sampled had more than five color printers or proofing devices in their shops. And most of the systems are not the same.
"If the RIPs are different, you get different results. So which one's right?" Zwang asks. "Processing variability was one of the things we saw most in the proofing study. The handling of overprints, in particular, was all over the place. The Altona suite deserves a lot of credit. It tests everything, including overprints, spot color handling and color identification," he says.