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What is Preservation?

The American Institute for Conservation (AIC) defines preservation as the protection of cultural property through activities that minimize chemical and physical deterioration and damage and that prevent loss of informational content. The primary goal of preservation is to prolong the existence of cultural property.

Basically, preservation is the way in which deterioration of objects is slowed. Over time, all materials will deteriorate, but with proper preservation that deterioration can be mitigated. With proper preservation techniques the lives of our historic and cultural materials can be prolonged and enjoyed by future generations.

Paper Preservation

Why does paper deteriorate?

Paper is made from organic materials. Prior to the mid-nineteenth century, most paper was made from linen rag pulp. Linen rag paper is exceptionally durable, and many books and papers that are several hundred years old are still strong and bright.

In the mid-nineteenth century, new processes were developed to produce paper from wood pulp. Although much cheaper to produce than linen rag paper, acids and other chemicals are needed to make paper from wood pulp. Chemicals within the pulp itself and chemical residues from the processing in these wood pulp papers react with light and the environment to produce and accelerate the acids that cause paper to yellow, turn brittle and eventually disintegrate.

Most papers produced since the Civil War are made from wood pulp. Therefore, many of the papers that are important to you and your family--birth records, letters, diplomas, military records, scrapbooks, newspaper clippings, and the like--probably have a high acid content that is progressively destroying the paper.

The hope in preservation is that damage to objects can be prevented by providing proper handling, storage and environmental conditions.

Environmental Conditions:
  • Objects should be kept in an environment with a stable temperature and relative humidity level
  • Temperature and relative humidity that are too high will result in a mold outbreak
  • Temperature and relative humidity that are too low will cause objects to become embrittled and result in tears and lost content
  • Maintain a stable temperature and humidity. Cool and dry is preferable, if you cannot maintain the perfect environmental conditions, then choose as low a temperature and humidity as you can keep stable. At the Archives, we maintain a temperature of 65F and 45% humidity.
  • Environmental controls also help prevent damage from air pollution, which adversely affects books, paper, art, and objects.
  • Limit exposure to all light.  Light damage is permanent and irreversible

  • Always use acid-free enclosures, folders, boxes and trays
  • Store objects flat if possible
  • If something is too large to be stored flat, it should be stored as a large diameter roll
  • Use metal cabinets and shelving that have a baked enamel finish

  • Provide rigid support to objects at all times to prevent flexing and possible tearing
  • Folding objects will eventually cause tears along creases
  • Objects should not be forced into spaces and containers that are too small
  • If an object shows signs of damage and is separating into pieces, do not repair it with tape. Consult a conservator.

For further information on Conservation and Preservation see the AIC website.

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© Copyright January 22, 2019 Maryland State Archives