ABSTRACT Many historical archives have been deteriorated by aging with time. Various kinds of defects such as worm-hole, yellowing, brittleness are observed and their severity was dependent on raw material type, storage condition, and so on. For a long-term use and storage, a proper preservation treatment is required. Many studies on preservation and conservation have been carried out on hanji which was made from mul-berry fiber, but there are few concerns on foreign paper. Therefore, aging and chemical strengthening treatment was done on paper made of bamboo and wood fibers depending on aging condition, the type and pickup weight of chemicals and treatment method. When methyl cellulose was treated with im-pregnation or brushing, the aged paper was strengthened effectively. The strengthening effect by chem-icals was dependent on the aged condition of the paper. Keywords: Aging, strengthening, cellulose derivatives, preservation, bamboo fibers 1. 서 론 종이 기록 문화유산은 단순한 종이로서의 존재가 아니라 만들어진 당시의 자연, 문화, 역사 등 현 세대를 살아가는 인류가 과거를 돌이켜볼 수 있는 역사적, 문화사적 가치를 지니고 있어 그 중요성이 매우 높다. 종이 기록물은 오랜 시간을 걸쳐 전해져 내려오면서 온전하고 양호한 상태로 존재하는 것 외에도 벌레에 의한 구멍, 황변, 불에 탄 흔적, 부스러짐 등 열악한 상태로 전해져 내려온 것 또한 많이 존재한다. 열악한 자료 중에는 역사적 가치가 매우 높은 것도 포함되어 있어 그 안타까움은 매우 크다. 시간에 경과에 따른 노화는 필연