Best characteristics in resolution fields showed the offset systems. This became clear at the investigations of the motive “Circles” and “Text”, whereby in the text fields the NexPress machine was in the leading group too. In the vignettes the conventional printing machines were best, but as in the resolution fields it is only a small gap to the NIP systems. In the images “Patches”, “Silver”, “Pigeons” and “Textile” got the offset systems with comparable screenings lower ranking then some of the NIP systems. Thus the statement is, that the digital systems do at least print in the images as good as offset systems with same screening, some do better. They partially obtain amazing, nearly halftone like illustrations, which show a detail reproduction, which was not reached by some conventional systems. To the results of the NIP systems should be said, that the NexPress machine convinced in all tests. If the evaluations in survey a got compared with the publication date of the engines, a clear connection can be recognized. As oldest machines Indigo UltraStream and Xeikon stand usually at the end of the rank order, followed by the newer Xerox, and the recently released NexPress. If this trend continues further, it will be interesting how good the new Xerox IGen 3 will be, which is still in the development phase. At this criterion it is disappointing that the new Indigo Platinum in survey b could not convince. Remarkably is the good evaluation of the HP system in survey b. That's a proof of the potential of the Inkjet systems, which however still has strong restrictions in speed and substrate choice. Further interesting will be which multi color development will show up, because the screening solution of a more than 4 color system is excitingly. For the master thesis samples from the new Océ 7-Colormachine (CPS 700) were available, but these were not used for the evaluation, because at this time the quality of the print samples where not satisfying and not comparable to the other systems that got evaluated.
Christian K. Schowalter, "Visual Comparison of Screening Quality in Digital Printing Systems" in Proc. IS&T Int'l Conf. on Digital Printing Technologies (NIP18), 2002, pp 682 - 686, https://doi.org/10.2352/ISSN.2169-4451.2002.18.1.art00062_2