From Commercial Printers to Flexographers, Agfa Leads in Screening Innovations
Monday, September 29, 2003
GRAPH EXPO (Booth #4041), Chicago, Illinois – September 28, 2003 – The same Agfa screening technicians who ten years ago revolutionized printing with the introduction of stochastic (FM) screening have come up with a new screening solution that gives printers the ability to differentiate themselves from their competitors with their customers. They can do this without added cost or adding anything extra to the press. The best part is, it's here now. From analog to Digital AM screening. In the early 90's, Agfa developed Agfa Balanced Screening (:ABS), an AM (amplitude modulated) screening technology. :ABS uses special algorithms and places dots of various sizes, depending on the tone value or image density, evenly in a grid. The PostScript-based conventional, halftone screening system uses supercell techniques and precalculated, balanced screen sets to deliver high quality color reproduction. :ABS-screened halftones feature clear-centered rosettes for smooth tonal gradations and tints. From AM to FM. In 1993, when Agfa introduced :CristalRaster, the frequency modulated (FM) screening solution, the way printers think about screening changed. :CristalRaster took a different approach to screening, providing an alternative to AM methods. With conventional screening, the halftone reproduction of a continuous tone image has an arrangement of equally spaced dots with sizes that change proportionally to the tone value of the original. With :CristalRaster, all halftone dots have the same very small size, but their number per surface area, or "frequency," varies according to the tone value to be reproduced, and their spatial distribution is carefully randomized. Because there are no line screens or screen angles, images are reproduced without rosettes. The result is moiré-free photographic images. Prior to the transition to Computer-to-Plate (CtP) platesetting, a printer's ability to hold dots in low-density areas was difficult. As CtP gained followers, FM screening also became more popular. " :CristalRaster was the first practical application of rosette-free printing. It has since spawned many imitators and Agfa considers this the sincerest form of flattery," said Agfa's Deborah Hutcheson, senior marketing manager, workflow and color systems, North America. From FM to XM. But AM screening still had its benefits. It was very predictable, and printed with equally smooth gradations. It is also easier to make on-press adjustments with AM screening than with FM. So Agfa technicians came up with an idea. What if the two could be combined in some way to satisfy all print applications? They came up with :Sublima. The cross-modulation of FM and AM screening into one. Patented by Agfa, :Sublima has won its share of praise from users and non-users alike. Almost all printers, once their presses are ":Sublima Certified," can reap the benefits of this cross-modulated screening solution with little to no effort on press and at no additional cost. "Customer response to :Sublima has been similar to the response we got five years ago when we put in the first visible light Galileo platesetter in the U.S. Once customers see a job run with :Sublima, they ask for all their work to be run that way," said Darren Yeats, General Manager of Quality Graphics in Roselle, New Jersey. Here's how it works: In the midtones, :Sublima uses AM technology for clear, accurate reproduction. In the highlights and shadows, :Sublima uses FM technology. Instead of simply switching between the two, :Sublima uses patented technology to smoothly transition from one to the other. Even though FM uses smaller dots, they are still properly aligned using the AM screen angles. This is known as XM, or cross-modulation, giving commercial printers the ability to generate line screens of 210, 240, 280 and 340 lpi. Because :Sublima RIPs at a moderate 2400 dpi to produce 340 screen ruling, it speeds RIPing time and platesetting. :Sublima also takes press characteristics into account so it compensates for dot gain and won't produce a dot that the press can't hold. Thus, every detail gets printed. Process tints, fine lines, even delicate typefaces print like solids using four-color process. Flesh tones are color accurate and visually smooth. Because :Sublima can hold the tiniest microdot on press, enlarging or reducing images has no effect on quality. This widens the variety of media that can be used at high line rulings, such as high-gloss coated stocks and translucent vellums. :Sublima for Flexo – Taking Package Imaging to the Next Level. :Sublima for flexo, which visitors to the Agfa booth can see up close, extends the tonal range, allowing marked improvement in extreme highlights and smooth, larger transitions in vignettes. With :Sublima, Flexo printers can achieve line screens of 150, 170, 190 and 212 lpi without any change in anilox rolls, helping create quality, eye-popping packaging materials that their customers demand. "Sublima lets flexo printers attain resolution and tone reproductions that were previously thought impossible," said Marek Skrzynski, Director of Graphics Development, City Stamp Works, Ludlow, MA. ":Sublima is a great way for packaging printers to stand out from the crowd and offer their customers something different," said Frances Cicogna, Packaging Segment Marketing Manager, Agfa. "In a highly competitive market, with clients always asking more of their printers, it is reassuring to know that :Sublima can offer so much for so little." Attendees can see the difference for themselves by visiting the ":Sublima Xperience" at Agfa's booth, #4041.