2014 Technical Innovation Award Winners Are Esko, SpotOn! Press/All Printing Resources Collaboration
The battle between efficiency and quality in packaging graphics is one that has raged for decades. Flexographers have been conditioned to choose one or the other. Equinox, a technology to reproduce custom spot colors with standard 7-color process, has proven to deliver both.
“It used to be that all flexographic package printing was done with custom spot colors,” recalls Esko’s Product Specialist-Color, Mark Samworth. “Each brand color was reproduced with a custom mixed ink and printed on a separate deck of the press. In the 1970s, 4-color CMYK was added for the reproduction of images. For the first time in flexography, color was being mixed on press instead of in the ink room.”
Esko set about investigating ways to print spot colors accurately using seven process colors instead of four. The goal was to mix colors on press instead of in the ink room, in a way that the consumer could not tell the difference when viewed on the supermarket shelf. Samworth notes that the term “fixed ink set printing” may be more descript of the economic benefits than the term “expanded gamut.” It’s about using the same seven colors on every job, eliminating the enormous costs associated with custom mixing in the ink room, custom setup on press and running every item as a separate job. It’s about gaining the efficiencies of a process color workflow without sacrificing quality.
Esko’s solution, a suite of software technologies called Equinox, converts brand colors as well as RGB or CMYK images to 5-, 6- or 7-color process. For its achievements, it has been awarded a 2014 FTA Technical Innovation Award in the prepress graphics category.
Instead of fingerprinting and profiling all combinations of CMYKOGV, four combinations of four colors are used:
“It was early in the inventive stage that we found these 4-color combinations of seven colors were capable of color accuracy in the range of custom mixed inks, but we didn’t really see the benefits of applying Equinox technology to images until we began testing with a major CPC on real, live jobs,” Samworth explains. “We realized that most package designs today contain photographic images, and how dull and lifeless the CMYK images looked on the 7-color package design. With 7-color gamuts that range an average of 70 percent larger than 4-color gamuts, we knew we had the potential for significant improvements in photographic image quality—we just needed to develop the math to make the conversions.”
Spot colors are typically matched in one of two ways: visually, using a subjective comparison of the colors and a keen eye, or by calculating Delta E through the use of a spectrophotometer. Regardless of the method used, there are a number of variables that make obtaining accurate, consistent results from job to job and press to press a difficult process. To make matters more complicated, neither of these methods provides any corrective actions to improve the determined color match.
All Printing Resources (APR) and SpotOn! Press decided to tackle this problem and developed SpotOn! Flexo. The invention was named the winner of FTA’s 2014 Technical Innovation Award in the Prepress Pressroom category.
SpotOn! Flexo is a color analysis software tool that uses a “Predictive Analysis” algorithm to determine the best ink density to achieve optimum color reproduction. Predictive Analysis is an adaptation of the Beer-Lambert Law, which is a relationship of ink film thickness and substrate white point, as related to L*C*h°. Unlike CMYK colors that have both ISO standards and specifications, like Flexographic Image Reproduction Specifications & Tolerances (FIRST), that suggest ink density starting points, the companies wrote in their awards submission, “Color reference guides and ink drawdowns come to press with no ink density information.” Furthermore, flexo’s color control options are limited:
- Increase ink density
- Decrease ink density
- Increase pressure or impression
- Decrease pressure or impression
SpotOn! creates what APR refers to as Optimal Ink Density. The measurement informs an operator if an acceptable spot color match can be achieved or improved with an ink density correction. The software also can be used in the ink lab before going to press, to see if an ink can successfully be matched ahead of time.
By tracking each measurement, SpotOn! provides a report from an entire pressrun that offers information on anilox roll, mounting tape, plate type, ink type, etc., on a color basis.