Best Practices

Preserving and Storing Paper in Library Collections

Gaylord Brothers

Documents, drawings, manuscripts, prints, pamphlets, periodicals, newspapers, postcards, and ephemera are typically made of paper—an organic substance that is vulnerable to deterioration over time.

All paper will deteriorate if mistreated or stored improperly. Some types of paper are particularly vulnerable—for example, the acidic wood-pulp paper that was produced throughout much of the 19th and 20th centuries. Unlike earlier papers, which were made of higher-quality fibers (commonly called rag papers), wood-pulp papers contain natural impurities and byproducts of the manufacturing process that break down to form acids in the presence of heat, light, and moisture. Pollutants in the air and/or direct contact with poor-quality storage enclosures also cause discoloration and embrittlement of paper.

There are a number of steps that can be taken to preserve susceptible paper collections. These include providing a cool, dry, clean, dark and stable environment; handling collections carefully; and choosing appropriate protective storage enclosures. Storage enclosures lessen the effects of fluctuations in temperature and humidity and provide protection against abrasion and handling.

Selecting Storage Materials

To provide long-term protection, storage containers and enclosures should be tailored to the size, condition, and anticipated use of the objects being preserved. They must also be durable and chemically stable so that they do not damage the materials they are meant to protect.

Paper materials are often stored using boxes, boards, folder stock and interleaving materials. The materials used to make these enclosures should be acid-free. Acid-free storage materials have a pH of 7.0 or higher. It is important to realize that although acid-free materials are not acidic when they are produced, they can become acidic over time.

For this reason, an alkaline reserve or buffer is often added to paper or board during the manufacturing process to neutralize acids that may form over time. This alkaline reserve is usually 2 to 3 percent calcium carbonate. Most paper collections will require buffered enclosures. While an alkaline buffer is generally desirable, there are a few types of collections that are sensitive to alkaline materials and should therefore be stored in pH neutral enclosures. These include blueprints, photographs and some textiles containing animal proteins, such as silk or wool.

Storage materials for paper objects should also be lignin-free. Lignin is a natural component of the cell walls of plants and trees. If it is not removed during manufacture, it can react with light and heat to produce damaging acids.

Clear plastic enclosures are particularly useful for objects that receive continual handling, are brittle, or must be browsed frequently. Polyester, polypropylene and polyethylene are three types of plastic that are inert, or suitable for storage of paper objects. They should be uncoated and free of additives. Various types of clear sleeves, folders and envelopes are made from these materials, or it can be found in rolls to use for encapsulation. Polyvinyl chloride (PVC) enclosures, sometimes referred to as vinyl, should be avoided and are not acceptable for use due to instability. Remember that plastic enclosures of any kind provide no protection from light, so items stored in plastic should be placed in boxes for long-term storage.

Preparing Collections

Once you have selected the appropriate storage materials, the documents and other paper items in your collection should prepared for storage.

1. Wear cotton gloves or make sure your hands are thoroughly clean to protect materials from the dirt and oil in your hands.
2. Do not eat or drink near collections.
3. Remove extraneous materials, such as paper clips, rubber bands, wrapping materials, old folders and any other item that is not pertinent.
4. Unfold and flatten papers wherever possible without causing damage to the folds.
5. Isolate newsprint when possible because it is highly acidic and will stain adjacent papers.
6. Note any brittle or badly damaged items and place them aside for evaluation by a professional.
7. Place identifying information on the object using a No. 2 pencil, if necessary.
8. To the extent possible, store objects of similar size and weight together.
9. Label boxes with adequate information about their contents.

If your collections are extensive, in poor condition or include items of value, keep in mind it may be advisable to consult a professional conservator before undertaking any procedures on objects of permanent significance.

For more information about proper archival care and storage of papers, photographs, books and textiles, request a complimentary copy of our Guide to Collections Care http://www.gaylord.com/catalog.asp? or visit us online at www.gaylord.com.

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