CCEW Community Event
Learn More about Paper Preservation in Your Community for CCEW 2019
You might think that paper is used mainly for books and newspapers, but historical documents of all kinds were created on paper. This includes old bank records, legal documents, and even blueprints for buildings! Over time, some of the paper used in these documents can break down and fall apart.
But surprisingly, paper that is over 200 years old can sometimes be in better condition than paper made only 50 years ago! The difference lies in the paper itself. Before the mid-19th century, paper was made from cotton and linen rags. These papers have long cellulose fibers that help make them more durable. Wood fibers eventually replaced cotton and linen, because it was cheaper and easier to use. However, the processing of wood to make paper results in shorter cellulose fibers that are not as durable.
Chemicals such as alum (a sulfate compound) were added when wood fiber paper was made. This helps prevent ink from soaking through the paper. Over time, moisture from the air reacts with alum to produce sulfuric acid. This acid breaks down the cellulose fibers, which creates even more acid. This cycle weakens the paper over time.
Acid-free papers delay this degradation. Alkaline compounds such as calcium carbonate (which is found in limestone and chalk) are added to the paper. These compounds react with the acids that are formed and prevent them from damaging the cellulose.
The paper in older documents cannot be easily replaced, but it can still be preserved. Important documents are typically stored in areas with low humidity, low temperatures, and away from light. This helps to preserve these documents for years to come.
Organize a trip to your local library, museum, or archive
Go to your local library, museum, or archive, and see what you can learn. Here are some questions you could ask:
- What are the oldest books or paper documents that they have in their collection?
- How old are these items?
- How often do people come to look at these items?
- What factors threaten the survival of these items?
- What precautions do they take to preserve these items?
- Is there anything else that can be done to preserve the information if the item is damaged?
Written by An-Phong Le and Cary Supalo
An-Phong Le, Ph.D is an Associate Professor of Chemistry at FLorida Southern College in Lakeland, Florida and Cary Supalo, Ph.D. is a Reasearch Developer at Educational Testing Service in Princeton, New Jersey.