TITLE:
Photobleaching characteristics of traditional Japanese paper in a museum environment
AUTHORS:
Kosuke Nakagoshi, Kunio Yoshizumi
KEYWORDS:
Traditional Japanese Paper;Photobleaching; Wavelength Sensitivity; Monochromatic Light; Visible Light; Blue Wool Reference; Dosimeter
JOURNAL NAME:
Natural Science,
Vol.3 No.11,
November
23,
2011
ABSTRACT: Photobleaching of aged traditional Japanese paper that has been thermally yellowed during storage for 200 years was examined from the standpoint of accumulated light radiation dosage in a museum environment. The light intensity was evaluated using a blue wool reference of the Japan Industrial Standards (JIS) as a dosimeter. The wavelength sensitivity of the photobleaching was compiled under monochromatic light radiation. Color changes in the specimens were measured in tristimuli values in color. by using a color analyzer. The aged pieces of paper were monitored continuously as they were photobleached under three different lighting conditions in a museum environment for 8000 h. The combination of the yellowness index changes of the aged pieces of paper and the color changes of a blue wool reference was interpreted as follows. Photobleaching was governed by accumulated light intensities and was independant upon daily lighting conditions. The wavelength sensitivity of the photobleaching of aged paper showed that the maximum effect occurred at 420 nm in the visible light range. The blue wool reference was confirmed to perform well as a dosimeter.