Preservation

While protection from environmental threats is the first line of defense for records in the Archives, there are other harmful processes to address.

Threats

Acid

In the mid-1800s paper manufacturing began using a wood pulp base and harsh chemical processes for bleaching. The wood pulp consists of short fibers that are weaker. It also contains impurities and a high acid content that combine to cause paper to deteriorate quickly. Many books and records less than 20 years old show signs of advanced aging due to high acid content. Newspaper print is an excellent example of the process. Some of the oldest records in the Archives—those dating to the 1840s and 1850s—are in better condition than more modern records. Older records are on paper made from rags consisting of long fibers and bleached by natural processes.

Mechanical and Chemical Sources

Paper clips, pins and staples cut through paper over time and rust. Rubber bands deteriorate and damage surrounding paper. Folded or rolled paper can cause damage when the records are opened. Non-record materials such as souvenir pins or badges, pressed flowers and product samples can chemically interact with paper to cause degradation.

Preservation Measures

Acid

The most comprehensive protection would include a systematic deacidification of all records. This could consist of running the records through a liquid bath with a high alkaline content. Alkaline is the natural opposite of acid and helps to balance the pH value. Unfortunately, this process is too expensive for most archives. We use the more common and affordable alternative of employing alkaline buffered or acid free boxes, folders, envelopes and sheets as well as chemically inert film/microfilm spools and cans. While not perfect, these measures expand the lifespan of the records.

Mechanical and Chemical Sources

The best measure against these threats is removal of the causes. After records are transferred to the Archives, staff and volunteers prepare them for public access. In some cases records are microfilmed. Preparation includes removing paper clips, staples and other fasteners and rubber bands as well as non-record materials. Records that have been rolled or folded are carefully opened and placed in archival quality folders and boxes where the folds relax over time. Some records are preserved using a process of encapsulation in which a document is placed between layers of polyester and sealed. This helps provide physical support for fragile records.
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Common Threats

Acid Content

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Daily Worker newspaper with headline "Roosevelt Truce Acts Against Strikes."
Newspapers have a high acid content that quickly causes the paper to yellow and become brittle.

Improper Folding

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A box on a table with folded files inside and large rolled up, long papers to the side (probably maps).
Rolled and folded records are flattened and placed in appropriate containers. This prevents damage caused by repeated folding and unfolding that occurs with use.
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