ブックタイトルConservation and Restoration of Western Paper

概要

Conservation and Restoration of Western Paper

Photo 1 Textbook published in 1941 (showa 16) JapanPhoto 3 Book made of Japanese paper published in1893 (Meiji 26)Photo 2 Microscopic image of document in photo 1.Short fibers are visiblePhoto 4 Microscopic image of document in photo 3.Long flexible fibers can be examinedpaper made during the Meiji periodsometimes contained wood pulp and theadded impurities lowered the quality ofJapanese paper. 9In acidic paper, hydrolysis breaks downthe cellulose in the paper leading to theweakening of the fibers. As a result, paperloses flexibility and in severe cases may easilydisintegrate. In the case of Japanese paper,different raw materials and productionmethods are used which means it does notage the way acidic paper does. As a test,a piece of acidic paper is soaked in waterand separated into fibers with a needle.Observation results show that acidic paperfibers are short and rod-like in shape whileJapanese paper fibers are long and flexible(Photos 1-4). This indicates that the acidattack which reduces paper strength in acidicpaper is a problem more severe in westernpaper than in Japanese paper. Yet, Japanesepaper coated with potassium aluminumsulfate for sizing is known to have a lowerpH and a faster rate of deterioration. 10Therefore it can be said that the durabilityof Japanese paper owes it to its fiber lengthand flexibility. However, Japanese paper thatincludes wood pulp and sized printing papermade in the Meiji era are prone to becomeacidic and lose paper strength.23