CLOSED-LOOP COLOR CONTROL — SMALL CHALLENGES, BIG REWARDS
“The beauty of these new tools is the ability to see these variables change and correct them in real time,” Welch says. “Without this type of system, print defects go unnoticed for longer periods of time.
“We do a pretty good job of matching our digital proofs, given the technology of proofing available today,” he adds. “To do this by hand on-press would cost much more in press time and waste. If we change inks or some other products, we are just a press run away from updating the prepress profiles for proofing.”
Speaking of Wisconsin printers, Menasha-based Banta has a total of nine closed-loop color control systems installed on web presses across its publication platform. Andy Johnson, vice president and general manager of Banta Publications-Kansas City, notes that the systems have a learning algorithm for ink presets. That algorithm changes when a job is saved, and the CLC system recognizes the difference between the saved settings and the presets on the fountains. The next time a job is run, the settings are more accurate.
Reduced makeready time and run waste were the primary justification variables for obtaining them, according to Johnson. Consistency of color, from the beginning of the run until the end, is the hallmark of closed-loop color control for many printers, Banta included.
“One of the ‘bells and whistles’ on the system that provided improvements is the measuring of dot gain,” Johnson notes. “That’s helped free our pressmen up, so they’re focusing less on color control. It’s a benefit we never had; before we had to manually measure our dot gains and determine if they were too high based on color reproduction and matching the proofs.”
The upshot: press operators can now take a proactive instead of a reactive approach and make improvements during the press run, says Greg Hain, pressroom manager for Banta. “Before, if we didn’t match a proof, an operator might say, ‘that’s as close as I can get it,’ because he may not have taken the time—especially on short runs of about 20,000—to perform a lot of hand-held readings,” Hain remarks.