The Study of paper surface efficiency

Paper surface efficiency (PSE) is a response resulting from the combination of paper gloss and oil absorptivity. A review of previous studies regarding the effect of paper surface efficiency on printed process color appearance is presented. This previous work related densitometric responses to PSE in terms of hue error and grayness. This current study investigated the PSE response in a similar manner, but densitometric responses were replaced by colorimetry. The colorimetric terms used were chroma (C*), huedifference (AH*), and lightness(L*). These correspond to hue error and grayness of the densitometric responses. Simple linear regression models relating the PSE and each response were constructed based on 13 kinds of paper printed with Hint cyan ink. The variable due to paper color was suppressed. The densitometric analysis generated results that verified Preucil\u27s investigation. These found that as the PSE increased, hue error and grayness decreased. The colorimetric analysis indicated a large color difference in the cyan ink due to PSE difference between coated and uncoated papers. This difference was more than 10 AE units. The difference was mainly due to the differences in chroma (AC*) and lightness (AL*); however, there was a small amount of hue-difference (AH*). The linear relationships between PSE vs. C* and PSE vs. L* were established and the correlation coefficient (r) was calculated. This analysis found that the correlations were significant and were used to predict the colorimetric responses (C*, L*) of an ink when printed on papers having different PSE. The models generated with the Flint Inks were tested with 9 additional papers printed at RIT with cyan ink to confirm the results and usefulness of the predictions. This analysis suggested the same concept as the previous one that there is a significant linear correlation between PSE vs. C* and PSE vs. L*- The straight lines that were generated were not the same for the two groups of prints that were investigated. This thesis contributes a useful framework for evaluating color using colorimetry as a function of PSE. With additional study, colorimetric analysis could become a better method for evaluating color in printing than densitometry