An inkjet web press that prints at commercial offset sheet-fed quality offers significant benefits.

Image Test LabsTM (ITL), a division of Technology Watch, LLC, announces that it has achieved an historic first in the printing industry by configuring an inkjet web press to deliver the image reproduction quality of a commercial sheet-fed offset press over a production run of three miles of paper. ITL printed a complex test image on each press side-by-side on the same sheet of paper, demonstrating that the output of the Screen 520 HD SC inkjet web press is suitable for commercial color work that requires offset sheet-fed quality.

“It is now possible for a production inkjet web printing press to behave like a sheet-fed offset printing press,” said Henry B. Freedman, ITL founding partner. “For the first time, regularly supplied off-the-shelf offset paper has been printed by an inkjet web press without requiring any special coatings, resulting in output image quality that matches or exceeds offset quality. Designers can now get much more of what they want from a digitally printed product, opening up a vast volume of work that can be run on an inkjet web press.”

Important benefits of using offset quality inkjet web printing include as a replacement for offset; as a complement to offset where the digital press prints a variable content signature bound into an offset work; as an alternative, so that the printer does not need to return to offset for subsequent, shorter reorder quantity runs; as a flexible daily option to solve deadlines and costs; and to deliver a lower cost, more easily-obtained and managed substrate paper inventory.

While the world is focused on digital, the vast majority of commercially produced printing is still done by offset lithography—perhaps over 90% globally. In a single month a single offset press typically can exceed the entire volume that most digital presses produce in their lifetimes. As digital print continues to gain market share, inkjet web press technology has still not been able to print real ink on conventional offset paper at production speeds at offset quality and volumes—until now.

How the test was constructed
ITL established three requirements that the inkjet web press must meet. First, the press needed to print directly onto off-the-shelf, Verso Sterling Ultra Gloss offset coated roll stock, with excellent adhesion—no smudging or smearing. Second, the output characteristics had to match offset quality: ink color gamut, color reproduction characteristics, appearance of the ink when dried, etc.—and with a uniform consistency over the entire three-mile length of the press run. Third, the inkjet web press had to include high-quality digital front end (DFE) electronics with the requisite range of control in order to set up and maintain press and image quality.

From ITL’s research, testing, and applications knowledge, they determined that at this time only one inkjet web press has these capabilities: the Screen 520 HD SC. The Screen SC polymer ink used in the test proved to be capable of printing directly on plain, lower-cost conventional offset papers.

“We noticed the offset match possibility when we measured the press output as part of the normal testing services we provide to commercial printing firms. We have shied away from trying such a match until now,” noted Freedman. “The fact that we can image directly to conventional offset web paper, with no precoating, and run the same paper on both the offset and inkjet web presses, combined with the very high color image quality of the Screen 520 HD SC, made us confident that the Screen press could stand on an even footing with offset printers. The SC ink resistance to abrasion and rub-off was so great that our independent testing facility did not believe that the samples they tested were inkjet.”

The very high score was repeatable. Image reproduction was extremely uniform. The ink and press are priced affordably for commercial printing volume applications. “We thank Cohber in Rochester, NY for their high quality offset skills in producing the challenging imagery the press had to replicate. We also thank Screen Americas for providing their 520 HD SC inkjet web press for our commercial length press image comparison run” added Freedman.

Test copies available from Technology Watch™
For a limited time, interested parties can receive a complimentary copy of the inkjet web match of an offset press. It is provided in the Technology Watch™ Special Issue Spring 2019 newsletter, which also delves into the test procedure in greater depth. People are requested to email their contact information to [email protected], to be the judge of this historic press run for themselves.

Holding the match press sheet, from left to right: Felix Bermudez, Sr. Sheet-Fed Press Operator, Cohber, Rochester, NY, Dr. Peter Crean, Dr. Eric Zeise, Dr. Peter Dundas, and Henry Freedman, all of Image Test Labs.