Assessing Perceptual and Physical Aspects of Printed Products By Quantitative and Visual Means

摘要

The assessment of the quality of printed materials has gone through many stages; from the first printed letters being visible or not visible on the first Guttenberg's presses, through controlling the amount of the ink on the substrate by measuring the density of the patches, then assessing color agreement by visual means and later introducing devices that could measure the color coordinates and color differences, all the way to sending digital files along the workflow and confidently reporting only the numbers without ever looking at the color at all. The ways colorimetric appearance is judged nowadays has been studied in great details for couple of centuries now and graphic arts industry implemented successfully these standards and processes. In this paper, we introduced methods that explain how to capture the visual impression of the studied effect, for example brilliance of metallic inks, and how to investigate ways to quantitatively describe the studied appearance. The study also describes the development of the visual scale for the effects, correlating the scale with instrumental measurements and the development of an equation that relates instrumental measurements and the visual judgments.