PRESERVATION IN A NUTSHELL
As with any cleaning or restoration method, test a small or unseen area first.
This report is based on notes provided by Beverly Halagarda, who attended a workshop present by the Orange County Historical Society on March 31, 1990. Jane Mueller delivered the lecture "Preservation in a Nutshell" based on her professional experiences at the Fullerton State Library. Her field of expertise is with preserving historical records on paper.
Preservation is the keeping of records that exist and the safeguarding of them from harm and decomposition. Items to be preserved include letters, documents, maps, books and photos, but not only older pieces. Contemporary items that would be of interest 100 years from now should also be sustained.
One key to protecting records is a good knowledge of paper. Most paper created prior to 1900 was made of cotton, which is acid-free and can conceivably last forever. Paper made of wood pulp is high in acid content. Newsprint is the worst, as evidenced by the ease and rapidity in which it turns dark and brittle, self-destructing. The acid content in older items must be neutralized, and newly-created documents must be on acid-free paper.
There are six steps in the preservation process: humidification, cleaning, de-acidification, encapsulation, labeling and storage. Depending upon the item, not all steps are involved each time. Ms. Mueller's intention is to provide the layman with low-cost tools and methods to protect their records.
For documents that are too brittle to unroll, humidification is the answer. For small items, a tupperware bowl with a lid and a grate in the bottom is used. A small amount of water is placed in the bottom, the item is placed on the grate, and the bowl is sealed for several days. Do not allow the document to come into direct contact with the water, or let it absorb too much water, or ink may run.1 When humidification is complete, the document is dried using acid-free blotters. Place it between two blotter sheets, and then surround the blotters with newspaper. Weigh this sandwich down with books.
The cleaning process uses a dry cleaning "Opaline" pad. Wear plastic gloves, and twist the cleaning pad over the item, releasing powder. Using fingertips and light pressure, stroke the powder in circular motions away from the center of the document. Do not use on desirable pencil markings as they will be erased. Archival supply companies have cleaning cloths to "dust" records.
Acid content in paper is one of the most destructive agents at work. Acid catalyzes the hydrolysis of cellulose fibers, causing it to break down in structure, and resulting in darkening, brittle paper. If an old book you are interested in buying exhibits these characteristics, don't purchase it. De-acidification of books is a major problem for libraries. Techniques are being sought for de-acidifying entire books, because the current remedy is a) un-binding, b) tedious page by page de-acidification, and c) re-binding. Due to the expense and difficulty involved, this work is better left to experts. However, for small projects, products can be purchased from archival supply companies that will work effectively.
Encapsulation protects the item from wear and mishap. Use polyester mylar in a thickness of 1-1/2, 2 or 3 mm. (Never use an acetate product, including the paper protectors in popular use. They harm paper). Measure and cut two sheets of mylar 1" larger than the document. Using 1/4" 3M 415 double sided tape, seal the document inside, making sure to leave a small gap (so the document can "breathe"). Round the corners off, and the job is complete.
The next step is labeling and storage. Labels should be clearly marked with a number that corresponds to the inventory file. The inventory should include a description of the item. Storage containers should be made of acid-free products. Inexpensive boxes can be constructed from acid-free matboard using linen tape. Storage areas should not be affected by temperature extremes, humidity, sunlight, dust or insects. In a home, a centrally located closet is suggested.
All materials deteriorate; a collector must maintain the best possible conditions for the longest possible life of each object. Preservation is paramount.