Development of a test suite for digital printing devices
Digital production printing devices are gaining a stronger foothold in the print industry, often complementing and sometimes rivaling offset printing. Now that digital printing has achieved production speeds and standards, a number of digital print testing programs are being developed that involve color and material tests and certification processes. This presentation describes one technical test suite that is been developed for digital print testing. This research presents the test criterion being developed and shows results from commercial systems. This research summarizes the efforts being made in the area of digital print certification by IPA and IDEAlliance in North America and FOGRA in Europe. The presentation describes the files being requested in the PIA/GATF Digital Benchmarking Study. This presentation reviews the applicability of ISO standards to digital printing.
The research describes a series of experiments that were conducted using output from eight digital presses, and comparing that to the same output from a Heidelberg XL 105 offset press. The study was comprehensive in nature covering all aspects of digital print production including color; sheet-to-sheet variability and physical properties such as rub resistance, cracking, fading, press speed and the ability to match GRACoL on a digital press. And for the first time in North America, deinkability and recyclability of prints from the various digital presses was measured.
Digital printing is often criticized as tending to drift, unable to color manage, unable to match Pantone colors, and many fear digital output cracks during folding in areas of high coverage. The results from a new series of tests demonstrates that these accusations are largely unjustified and that digital printing matches, and in many situations surpasses, offset in terms of color, print quality and durability.
The gamut of the digital presses matches that of a conventional offset press and is quite often larger. Digital presses were also more able to better reproduce in gamut Pantone® colors built from CMYK and with a lower color deviation than the offset press used as a comparator. The Resometer™ test gave very interesting results. The digital presses from one manufacturer were very close to produce offset like print quality.
The toners used in the studied digital presses showed a much better fade resistance than the pigments used for offset printing.
Depending on the digital print device studied the rub resistance of the digital prints is similar or better than that of offset print.
Overall it can be said the print quality of digital prints is in many cases comparable to offset, but improvements are still needed to completely match the abilities of the offset printing process.
