One of the most important procedures within the Archives is the preservation and conservation of old documents and photographs. Depending on the age of the document, preservation can be very time consuming. It is important to use the correct procedures in order to retain all of the information from the damaged document.
Paper quality has declined since the 1850’s, prior to the 1850’s paper was made primarily by hand, using cotton and linen rags with a calcium carbonate wash. Paper documents are very delicate and must be stored in acid-free folders and boxes so they don’t deteriorate.
Some of the major contributors to deterioration are wide variations of temperature and relative humidity, atmospheric pollutants and light exposure. High humidity increases the growth of mold and the depletion of the paper’s molecular structure, while lower humidity increases the brittleness of the molecular structure. Pollutants such as dirt, dust, soot and tar embed themselves within the fibers of the paper, which weaken the paper structure. Too much light exposure can result in chemical reactions that cause the paper to deteriorate.
When documents have been rolled up for an extended period of time, they need to be flattened and placed into Mylar. Mylar is a sheet of plastic that can be used to preserve brittle documents. The most efficient way to flatten a document without any damage is to humidify the document.
- Fill a plastic container with a quarter inch of water.
- Place the document on a wire rack, so it does not get wet.
- After 24 hours the fibers within the paper are softer and easier to flatten.
- Remove the document from the container and place it between two pieces of acid free paper for another 24 hours, use weights at the corners of the document to keep it flat.
After flattening the document it needs to be encapsulated in Mylar.
These procedures make researching easier for patrons. Have any questions about document preservation and repair? Contact us at firstname.lastname@example.org.
Written by Peter Dewan