In recent years the differences in image quality of digital printers relative to offset lithographic presses have been becoming ever more subtle. In 2007 experimentation was conducted within the Print Industry Center at the Rochester Institute of Technology examining this difference. It was found that there were significant differences in perceived value of prints made on digital versus offset printing equipment with the prints on coated media made on offset equipment being generally preferred, while the prints on uncoated media made on digital printers were frequently assigned higher value. The results of this experiment were possibly compromised by the reality that there were unintended shifts in the color balance of the prints made on some of the digital equipment relative to the offset reference prints. The present study was conducted to examine the effect of these unintended color shifts, to further examine the effect of the media on the perceived image quality differences between high-end digital presses and offset lithography, and to look at the impact of the skill of the observers on the perceived image quality differences. The experimental results suggested that the color balance shift had minimal impact on the perceived image quality differences, though contrast played a significant role. The media also had a strong effect on perceived quality. Unsurprisingly, skilled observers tended to rate images more critically than unskilled participants, though this effect was only statistically significant for some of the photo-based images.
Susan Farnand, "Further Investigation into the Image Quality Differences between Digital Print Technologies and Traditional Offset Lithography" in Proc. IS&T Int'l Conf. on Digital Printing Technologies and Digital Fabrication (NIP25), 2009, pp 515 - 520, https://doi.org/10.2352/ISSN.2169-4451.2009.25.1.art00031_2