Get Rid of the Guesswork

There can be little argument about the role of proofing in package-printing workflows. An acceptable proof has three essential qualities: it’s fast, affordable, and color-accurate. Achieving the closest possible match between the proof and the printing press is the objective here, with the larger goal of ensuring a predictable, repeatable printed result throughout the print run. A proof that matches the press run saves printers time and money, and generates less waste on the print job, thereby keeping customers satisfied. Trade shops that deliver fast, color-accurate proofs that do not break the bank not only fulfill a commitment to their printer customers, but also enable those printers to honor commitments further along the supply chain.

With so much riding on the quality of the proof, trade shops must be able to predict how the press will perform on various substrates, including hard-to-handle materials like clear plastic and foil. Effective proofing solutions are engineered to remove variability from the process and integrate easily with digital workflows. Despite all the buzz about monitor-based proofing, most package printers continue to provide what most high-value brand owners still demand—a hard-copy contract proof output on the actual substrate to be used for the package, or, increasingly, an accurate inkjet simulation.

Making the transition

“There isn’t a more important product we offer than a color-accurate contract proof,” says Ken Pavett, president and CEO of FlexoGrafix, a flexographic color separator from Wood Dale, Ill. The company provides what Pavett describes as “creative separation engineering,” because its customers (flexographic printers) receive digital artwork from designers that is typically separated as four-color process files. FlexoGrafix brings its flexo printing and prepress experience to bear by engineering all files so they are easy for the printer to reproduce without sacrificing the integrity of the designer’s intent.

The company provides a variety of proofs depending on the nature of the project and its customers’ preferences. Not every project warrants a contract-grade proof, though. “Some of our less color-critical customers will request PDF proofs because they’re quick, portable, and inexpensive,” Pavett says. “But if it’s process work, most of our customers want to use a contract proof for communicating color.”

The decision to do without a contract proof, relying on PDF “monitor proofs,” risks print buyers’ dissatisfaction with the reproduction of the printed project. “Most monitors are not color-managed to the color space of our customers’ flexo presses,” Pavett explains. “You could view a PDF on any monitor and predict what it’s going to look like, but you’re taking a big risk that the proof won’t represent what the press will print.”

FlexoGrafix takes a “scientific approach” to proofing, says Pavett. This “by-the-numbers” method substitutes mathematical certainty for guesswork and is subject to strict process controls designed to ensure maximum consistency.

“We put each proof through a range of tests against our standards,” he says. “Every proof we ship has a certification label validating that it matches the criteria (dot area, solid ink densities vs. FTA’s FIRST standards, Delta E) we and our customers are looking for.” FlexoGrafix then assigns the proof a passing grade, based on its internally developed color target with a scanning spectrophotometer.

Unless a project requires a Kodak Approval, the need to proof on the actual substrate is becoming less important for FlexoGrafix, Pavett says. This is a function of the company’s investment in the color management tools integrated within EskoArtworks’ FlexProof proofing solution, based on the manufacturer’s Kaleidoscope color management system, a module within EskoArtworks’ Software Suite. “We’ve had its entire workflow for three years,” Pavett says. “FlexProof drives FlexoGrafix’s HPZ2100, two HP5500 plotters, and a pair of Xerox 2135 color printers that the company uses for internal purposes. It also drives the Kodak Approval halftone device.”

Prior to implementing color management about 14 months ago, FlexoGrafix’s primary proofing device was its digital halftone proofer. “With this technology, it was important to laminate the proof onto the customer’s stock so that it would represent the hue of that stock,” Pavett explains. “In our current product portfolio, however, our customers actually prefer our Kaleidoscope proofs driving an HPZ2100 printer for its color accuracy on both halftone images and Pantone colors.

“As a result of these improvements... our customers can come up to color and achieve an acceptable match to our proof on the first try more than 90 percent of the time,” Pavett states.

Maintaining color accuracy

Color accuracy is also the name of the game at CyberGraphics (Memphis, Tenn.), a trade shop specializing in flexible packaging on film or paper for salty snacks, confectionery products, pet foods, etc. Kevin Bourquin, prepress manager, ensures that files from outside designers are appropriately color-managed in preparation for the flexo process, and that files are correctly screened.

“We print on clear film with white ink, matte films, and clear films that are laminated to metallized films, white films, or even films laminated to paper, so we have to have a wide variety of packaging structures profiled to be able to accurately predict how process colors will work—even spot colors and screens of spot colors,” he says. “Our job is to make sure fluctuations in the process colors won’t produce massive variations in the image.”

Among the most challenging proofing issues for CyberGraphics is replicating significant dot gain with flexo, which can require a fair amount of tweaking, Bourquin says. “We spend a lot of time manipulating different images. We also know from experience that the flexo process won’t produce linescreens that are as crisp as the proof, so we have to apply ‘noise’ to our profiles to achieve the most accurate results,” he explains.

CyberGraphics measures color saturation and hues and keeps a close eye on gray balance, which it measures on every proof. This is because the flexo process produces wide variations in gray balance from job to job, and because “it’s a good indicator whether our proofing system is running accurately,” Bourquin adds.

CyberGraphics uses inkjet technology exclusively, a decision driven, in part, by the need to cut costs. The company also uses GMG’s ColorProof software to drive its HP Z3100, and Epson 9800 proofers, which it uses interchangeably, depending on the requirements of the job. The company chose GMG ColorProof for its ability to simulate dot structures, metallic inks, and substrate texture.

The biggest improvement with GMG ColorProof is early detection of screening problems, such as moiré and trapping errors. “We definitely catch more things since we implemented GMG ColorProof three years ago, ” Bourquin adds.

CyberGraphics’ proofing systems are all closed-loop, and feature proof verification capability. According to Bourquin, this reassures the CPC and provides CyberGraphics with data used to recalibrate its systems. “We always confirm color, and at the end of the process,” he says. “Not only do we image a color-accurate digital proof, but we measure it back into the system and compare it to a standard to make sure what we’ve delivered is truly what we said it was.”

Remote proofing

CyberGraphics and FlexoGrafix are keeping their eyes on remote proofing, and both consider it an option down the road. CyberGraphics has experimented with GMG’s ability to do remote hardcopy proofing with the HPZ3100 series. FlexoGrafix continues to monitor the trend toward soft remote proofing while waiting for customer demand to build.

Analog proofing used to entail significant material waste and was labor-intensive. Digital proofing and color management have changed all that. Accurate proofing is less difficult than it used to be because proofing vendors have supplied devices and color management technology that allow better matching to proof on both process and spot colors.

“Today, the technology is the investment, not the labor,” Pavett says. The goal, however, remains the same. “The accuracy of our proofs, combined with our creative separation engineering and first-rate customer service, is the glue that keeps our customers’ relationships together.” pP