|Lesson:||Lesson 3: Preservation|
|Topic:||Preservation of What?|
Preservation of What?
Assuring that archival collections are preserved is one of the primary activities of archivists. Archival materials require preservation in order to keep them in the best condition possible for as long as possible. Even formats like paper and photographs need special care and handling to assure that they survive as long as possible.
Paper created before about 1840 was made primarily from cotton and flax rags turned into pulp. This paper is strong and quite stable. When stored correctly, this paper can last for hundreds of years.
After 1840, modern paper production used trees as the source of pulp. This paper produces acid when exposed to air and moisture. Depending on the production methods and materials used, this paper may start to show signs of deterioration after only 10 to 50 years.
Photographic images are formed by the action of light on chemical compounds. Photographic materials are made up of many layers (supporter, binder, and image-forming layer), each of which responds differently to the environment.
The supporting and binding layers can readily absorb and lose moisture, which can lead to deterioration. If any one of these layers fails, the image can be lost.
No matter what kind of material you are processing, preservation actions are vital to slow further deterioration. Nothing can completely stop deterioration, but good preservation practice can slow down the ravages of time dramatically.
Paper ingredients once included flax, hemp, straw, and cotton fiber. Today's wood-based papers deteriorate more quickly.