The high-quality inkjet market is expanding and a large number of printers and print substrates are available. This makes the ability to analyse current print quality and quantify improvements increasingly important. For print quality evaluations, technical measures are preferred since they are repeatable and less time-consuming than visual assessments. The question is which print quality factors best describe the overall visual appearance of an inkjet print? McFadden and Donigian (1999) consider print density and colour-to-colour bleed the most important visual print factors for inkjet prints. This has been adopted by others (Svanholm, 2004; Superka, 2000), who evaluate inkjet prints in terms of these factors. The aim of this investigation was to identify the most important print quality factors for high-quality inkjet prints and thus define a quality space that characterises the print result in relation to the visual appraisal. Sample material has been obtained by printing on nine coated inkjet papers in three desktop inkjet printers. Technical quality factors assumed to be relevant for inkjet print quality, such as mottle, sharpness, grey balance, gloss, density and colour gamut were obtained from the printed samples using technical measurements. Mottle was measured in both full-tone black and full-tone green. Sharpness was measured from two regions, a black line on yellow background and a black line on an unprinted area. From each region two measures were obtained, raggedness and blurriness. Four sharpness metrics were thus produced, referred to as black raggedness, black blurriness, colour raggedness and colour blurriness. Grey balance was defined as the chroma value of a 40% CMYK-grey printed area. Gloss was measured in full-tone black and full-tone green at three different angles; 20°, 60° and 75°. Density was measured in full-tone cyan, full-tone magenta, full-tone yellow and full-tone black. The colour gamut was obtained by measuring colour patches representing the colour gamut surface and from these calculating the colour gamut volume.
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