Preservation Enclosures 101 (Items of the Month)

By Christina Amato, Book Conservator, Gladys Brooks Book & Paper Conservation Laboratory

How simple is a box?

It is often overlooked, but creating appropriate enclosures, or housing, for collection materials is an important part of the work of a library conservation lab. A well made box can have a huge impact on the longevity of a book. Conservators have to weigh many factors when deciding what kind of enclosure is appropriate to use. When is a clamshell box the best choice, and when would a phase box be better? Scroll down to see some examples of typical enclosures made at the Gladys Brooks Book and Paper Conservation Laboratory.

First, the clamshell box. This type of enclosure is one of the most traditional you will find in a library. Each one is custom made for each book. They provide an enormous amount of protection to the book, and can be very attractive. However, they are quite time consuming to make, and add to the width of the book. For one or two books, this may not be significant, but for a large collection, and if you have limited shelf space, it can become an issue.


Three books in clamshell boxes, left. An open box, right.

Consider the pamphlets below, which are housed in brittle and crumbling old folders. They no longer provide adequate protection to the material inside, and in some cases are actively causing damage. Clearly, new enclosures are needed. However, there are thousands of these pamphlets in the collection, and it would be impractical to create clamshell boxes for each one.


Pamphlets in need of new housing.

Enter the phase box, or wrapper. These are constructed out of a thin cardstock and take up much less room on a shelf than a clamshell box. They also take a fraction of the time to complete, though each is also custom made for the material within.


Phase boxes.

Phase boxes are a good solution for this kind of collection. However . . . are there any downsides to having rows and rows of items that look like this?

Rows of phase boxes.

Rows of phase boxes.

What if your collection looks like this?

A shelf with visible spines.

A shelf of books with visible spines.

Conservators at the Folger Shakespeare Library in Washington, DC, developed a “visible spine phase box” similar to a traditional phase box, but which incorporates a clear piece of Mylar. This way, you can see what is inside the enclosure. Not only can this be more appealing visually than a row of undifferentiated cardstock, but it can be useful in monitoring the condition of a book. And, of course, it is immediately obvious if the box’s tenant has gone missing!

Books in visible spine phase boxes.

Books in visible spine phase boxes.

Occasionally, an item will enter the lab that doesn’t fit into any of the usual categories. Below is a Sinhalese “Ola,” or a palm-leaf manuscript, written in 1720. The mailer bag it arrived in doesn’t quite meet the standards for an adequate enclosure.

An ola in a mailer bag.

An Ola in a mailer bag.

Our solution was to make a modified clamshell box; the sides are cut away so that it is easy to reach in and safely remove the item; the cover is built up to provide room for the protruding button and string on the cover; and the sides are covered with a smooth Tyvek to protect the fragile palm leaf edges.

An Ola in a modified clamshell box.

An Ola in a modified clamshell box.

If you have an entire box full of Olas that require re-housing, however, like the unfortunate ones below, that may prove to be too time consuming.

Many unfortunate Olas in need of rehousing.

Many unfortunate Olas in need of rehousing.

The solution here was to modify a commercially made enclosure with separate compartments made out of Valera foam. Each piece is protected, and using a pre-made, standard sized box saved time.

Olas in a modified commercially made enclosure.

Olas in a modified commercially made enclosure.

These are just a few of the typical sorts of enclosures you will encounter in a library. Labs will often make their own modifications and improvements. Whether it be simple or very complex, the box plays a crucial role in preserving fragile materials.