DARKENING OF PAPER FOLLOWING EXPOSURE TO VISIBLE AND NEAR-ULTRAVIOLET RADIATION
S. B. Lee, J. Bogaard, & R. L. Feller
ABSTRACT—In a series of experiments using three different sources of visible and ultraviolet radiation, post-irradiation darkening at room temperature of water-leaf papers made from various pulps is shown to be chiefly influenced by the content of lignin and by the pH of the test sheets.
2. RESULTS AND DISCUSSION