Process control and calibration are the keys to accurate proofing for graphic reproduction.January 2011 By Jean-Marie Hershey
The goal of an effective proofing system is to ensure predictable, repeatable results throughout a print run by achieving the closest possible match between the proof and the printing press using color management and screening techniques. An effective proofing system will be able to accurately reproduce trap and overprint characteristics, together with the fine lines and text that are critical in package and label design. Inks or dyes, media, RIPs, and color management tools all will play important supporting roles.
As is the case with any worthy goal, getting there is the challenge. With proofing, it requires shifting our attention to process control and calibration as the keys to achieving the best possible press-to-proof match. "Chasing" the proof on-press has always been problematic—not to mention time-consuming and expensive—for the simple reason that proofing devices typically behave much differently than printing presses. Absent appropriate process controls, errors in packaging preproduction can be carried through and multiplied across the various print disciplines, substrates, and color sets employed to identify a given brand and its extensions. This could have disastrous—and costly—consequences in terms of time, labor, waste, and rework.
State-of-the-art proofing in action
Fourth-generation, family-owned Hammer Packaging is among the largest and most forward-thinking producers of high-end packaging decorating in North America. Roughly 70 percent of Hammer's capacity supports the production of litho-based labels for the food and beverage industry, with web offset and flexo-printed labels accounting for the remaining 30 percent. The company also is said to be the world's largest producer of premium seed packets. Customers include Gatorade, Coca-Cola, Pepsi, Campbell's, and many other well-known brands. The $100 million company employs more than 400 people at three plants in the Rochester, N.Y. area.
Hammer operates both Epson inkjet (with GMG RIP for color management) and Kodak Approval digital halftone proofing systems. The company uses off-the-shelf conventional and UV sheetfed inks by the Flint Group that conform to the ISO 12647-2 ink specification defining the L*a*b* colorimetric values for CMYK and RGB overprints. Plates are imaged on a Kodak Magnus VLF platesetter, which anchors the company's EskoArtwork prepress workflow. While the company produces some inkjet contract proofs, it more often relies on its Kodak Approval to generate hard copy contract proofs/mockups on the actual substrate to be used in production.
In Hammer Packaging's fast-paced world, says Prepress Manager Bill Pope, state-of-the-art proofing denotes "having the capability to proof accurately on a wide variety of substrates, targeting all the printing systems and ink sets we use."