Volume 5, Issue 2 (February 2008)
Diffuse Versus Directional Brightness Measurement Comparison for Paper
Despite claims of a paperless society, worldwide paper consumption is expected to grow 50 % by 2010 (World Resources Report 1998–99, “Environmental Change and Human Health,” published by Oxford University Press, New York, for the Wold Resources Institute, ISSN 0-19-521-408-0). As markets become more closely connected, through globalization of industrial supply, the need for standardization is greater than before. The paper industry has established standards for identifying the quality of paper. However, in terms of paper brightness, which is one of the main characteristics used to determine a paper’s price and quality, there is often uncertainty about which standard to follow. This is due to the fact that currently there are two geometrically different methods for testing the brightness of paper: ISO and TAPPI. The differing brightness values can misinform consumers. This report tests both methods and finds a linear relationship that can be used to convert between the two standards.