A print buyer's choice of printing, color reproduction, and screening technologies may all have an impact on the perceived quality of the resulting images. This paper presents the results of an experiment that assessed the impact that these factors on image preference. Six samples of the same design were prepared using (1) Flexography and Lithography, (2) CMYK (4-color) and Expanded Gamut (7-color) color separations, and (3) traditional (AM) and enhanced (Concentric for lithography, High Definition for flexo) screens. The samples were evaluated by 53 industry professionals who force ranked them under real world conditions (uncontrolled lighting, unscreened participants, etc.). Rankings of participant preference reflected the participant's subjective assessment of image quality and appeal.
A nonparametric test for statistical significance (the Wilcoxson paired difference test) showed several significant differences in participant preference based on the technologies used to produce the samples. Expanded Gamut (7-color printing) was preferred to CMYK regardless of the printing technology or screening used to produce the samples. Offset using Concentric screens was preferred to Flexo using High Definition screens. On the other hand, when High Definition Flexo was compared to standard Offset using AM screens, participants showed no significant difference in image preference.