Enclosures

Boxes and other enclosures are an effective way to preserve collections. They protect against the damaging effects of light, fluctuations in temperature and relative humidity, direct handling, and water. Some items, such as musical scores, have multiple parts and cannot be bound together, and need an enclosure to prevent components from being separated and lost. And some books might have physical characteristics that could cause damage to neighboring books, such as sharp clasps or powdery leather. The Preservation Department utilizes a variety of enclosures that provide different kinds of protection.

Storage materials that are acidic or contain lignin can migrate to library materials and cause damage in the form of discoloration and deteriorating “acid burns.” Preservation uses acid-free papers and boards that have a pH of 7.0 or higher. Lignin is a natural component of wood fiber that becomes acidic and causes paper to become brittle. Lignin can be mostly removed from pulp during manufacture to produce a more durable paper.