Prediction of Print Quality Using the Components of Formation of Unprinted Paper, 2000 International Printing & Graphic Arts Conference Proceedings

Jean-Philippe Bernié, Ian A. Journeaux, John W. Stolarz, W.J. Murray Douglas--End-use properties of paper, mechanical strength and print quality, are strongly affected by the nonuniformity of sheet structure, or formation. Satisfactory relationships have not been established because of the difficulty of quantifying formation. Standard instruments provide a single-number formation index which is blind to scale of formation. In a new technique the intensity of local nonuniformity of formation is partitioned as a function of scale of formation over a wide range of scale. This technique shows that properties are typically controlled by formation components over just a limited range of scale of formation, specific to the paper grade - paper property combination.

This method is now extended to predicting print quality from the formation of the unprinted paper. The MSU (Measurement of Surface Uniformity) test on unprinted paper is a good predictor of print quality. By relating the MSU index to the components of formation, the components in just the 2- 3mm range of scale of formation are identified as dominantly controlling printability (R 2 of 0.76). Also, there is a high sensitivity in the prediction of MSU index from the 2-3mm components of formation, which moreover are determined with 3 to 6 times the precision of the MSU index. Use of this new method of partitioning formation of unprinted paper provides the needed simple instrumental method for predicting printability.