New Instrumental Determination of Solid Print Nonuniformity, 2001 Coating Conference Proceedings

Jean-Philippe Bernié, W.J. Murray Douglas--As an adaptation of our technique of partitioning formation nonuniformity, print mottle nonuniformity has been partitioned into its components as a function of scale of print mottle, from 0.3 to 19 mm. For a set of 14 Prufbau strips the "components of print mottle "scale of print mottle" technique was used to establish at which of 10 values of scale over this 0.3-19 mm range are the print mottle components important for visual perception. Both as a function of print mottle scale and between the 14 strips, variability of solid print nonuniformity is high, +/- 30%. Correlation between these 10 print mottle components and visual ranking is highest (R 2 of 0.83) at print mottle scale of 2.5 mm, decreasing to much lower correlations at both limits, 0.3 and 19 mm. In the central region of scale of print mottle from 1 to 2.5 mm, these correlations are high, with R 2 of about 0.8. Also sensitivity of the 2.5 mm component to subjective print mottle ranking is high, a change of 1 ranking level out of 4 corresponding to a 27% change in value of this component. As the 2.5 mm print mottle component is determined with high precision, this technique constitutes an effective method for instrumental determination of print mottle.