Preserving Evidence of Use: The Conservation of a Teaching Collection of Medieval Manuscript Fragments

This is a guest post written by Kathryn Kenney, the Advanced Book Conservation Intern in the Conservation Division at the Library of Congress. Kathryn is completing an M.A. and C.A.S in conservation at the Patricia H. and Richard E. Garman Art Conservation Department at SUNY Buffalo State College.

Prior to the rise of printing, everything was written by hand. Medieval libraries were filled with manuscript books and documents but many of those items no longer exist in their original form. Some were thrown away when their contents became outdated or not useful anymore. Others were discarded and replaced with printed books. But some were taken apart, and their covers and pages were repurposed. Some books had beautiful illuminations that were cut out and framed. In many cases, book pages were recycled and used as covering material, end leaves, or other components of new bindings. Some of these pages, which are called fragments, can be found in the collections of The Library of Congress. In the Conservation Division at LOC, a project is currently underway to conserve these fragments so that they can be more easily shared with researchers and students.

As the Advanced Book Conservation Intern at the Conservation Division at The Library of Congress, I have had the privilege of working on multiple projects with different members of the conservation team to learn and expand my conservation skillset. For one of my first projects I joined book conservator Cathie Magee in the treatment of some of the medieval parchment manuscript fragments from the Rare Book and Special Collections Division.

Project Introduction

Before the manufacture and use of paper became widespread in Europe, everything was written by hand and parchment was the dominant writing surface. Parchment is a fascinating material made from the skins of domesticated animals, usually calf, sheep, or goat. The skins are cleaned and stripped of hair and flesh and then stretched tightly and dried under tension. The resulting material is strong, durable, and flexible. This material is so durable, books written on parchment can last for hundreds of years .

The Rare Books and Special Collections Division has several small collections of parchment fragments that add up to hundreds of items. Notably, the Lessing J. Rosenwald Collection containing 2,653 books and manuscripts from the last six centuries. The collections consist of both individual pages from books as well as single page documents such as deeds. Some of the fragments have been described in Seymour de Ricci’s Census of Medieval and Renaissance Manuscripts in the United States and Canada, but many were not yet catalogued by the Library, and none have been digitized. The main condition issue preventing the fragments from being processed were deep, stiff folds that obscured writing. The rigidity and strength of parchment means that it is highly resilient to damage like abrasions and tearing, but it also means that if creased, the folds can become entrenched. Many of the parchment documents were stiffly folded and required treatment before they could be properly digitized and catalogued. Several of the documents also had insect damage and tears that needed to be repaired.

This project presented a unique opportunity to learn more about the re-use of parchment fragments over time and to analyze how parchment responds to conservation treatment. With Cathie’s guidance, I was able to explore different treatment methods for each individual item and to experiment with different techniques and materials.

Humidification

One unique characteristic of parchment is its sensitivity to changes in relative humidity. Parchment expands in humid conditions and contracts when the air gets dry and conservators can use this to our advantage. By carefully controlling the introduction of moisture and then allowing the parchment to slowly dry under restraint, hard creases and folds can be safely flattened without causing tears.
There are many different humidification methods, and for this project, I was able to explore a few of them.

• Gore-Tex Sandwich
Gore-Tex is a vapor-permeable material; the same material is used to make high-tech rain protective outdoor gear. With this method, a piece of Gore-Tex is placed over the crease or fold. The Gore-Tex allows moisture vapor to pass through, allowing for gentle humidification. A dampened blotter is placed on top of the Gore-Tex. A piece of polyethylene sheeting is placed on top to prevent evaporation and light weights hold the layers in place. This allowed for controlled humidification and the creases relaxed nicely.

Kathryn Kenney applying a Gore-Tex sandwich to a parchment manuscript fragment. Photo credit Cathie Magee.

Kathryn Kenney applying a Gore-Tex sandwich to a parchment manuscript fragment. Photo credit Cathie Magee, 2021. 

 Diagram of a Gore-Tex sandwich for humidification. Credit Kathryn Kenney

Diagram of a Gore-Tex sandwich for humidification. Credit Kathryn Kenney

• Direct application of Water and Ethanol
Using a small watercolor brush, I lightly applied a mixture of deionized water and ethanol directly to the crease. This method was only used on small, lighter creases where there was no media, as the media can be affected by these solvents.

• Humidification Chamber
For fragments that required overall humidification, Cathie and I built a humidification chamber to slowly and gently introduce moisture to the fragments evenly. For this method, we used a shallow plastic tray with just enough hot water to cover the bottom of the tray. Above the water we suspended a plastic grid to raise the parchment fragments well above the water level. The fragments were sandwiched between two pieces of polyester webbing and placed on the platform. A clear sheet of acrylic covered the tray to seal the chamber, allowing me to watch the parchment slowly relax in the humid enclosure.

Parchment manuscript fragment in a humidification chamber. Photo credit Kathryn Kenney.

Parchment manuscript fragment in a humidification chamber. Photo credit Kathryn Kenney, 2021.

Diagram of a humidification chamber. Credit Kathryn Kenney

Diagram of a humidification chamber. Credit Kathryn Kenney, 2021.

• Flexible Gels
Cathie previously did research into the use of high-acyl Gellan gum in the conservation of parchment. Gels are often used in conservation to slowly release water or solvents in a controlled manner. We made a batch of high-acyl Gellan gum in a 1:1 deionized water and ethanol mixture. Once set, we used small pieces of the resulting gel applied directly to the parchment to locally humidify creases. The gel did effectively soften the parchment, but it introduced more moisture than the other humidification methods.

A beaker of high-acyl Gellan gum on a hot plate. Photo credit Kathryn Kenney

A beaker of high-acyl Gellan gum on a hot plate. Photo credit Kathryn Kenney, 2021.

Flattening

Once an area of parchment was humidified, I gently unfolded the creases and immediately placed the item in a controlled setting to dry and flatten. There are a number of ways to control the drying and flattening process and for this project Cathie and I tried three different methods.

• Flattening under pressure
For the creases that I humidified using direct application of water and ethanol, I immediately placed a small piece of felt and a light weight over the area to allow for drying under pressure. This method was also used for some of the fragments humidified using local humidification chambers.

• Flattening under tension: Clips and pins
This method allows the parchment to dry under tension in a method similar to the process used to create the material. Tensioning ideally applies even force across the material in all directions, encouraging the protein fiber bundles to align and dimensional variances to decrease. Specially prepared clips are positioned around the parchment fragment. Once the clips have been positioned, specimen pins are placed through the clips and into a support board at an angle to apply tension uniformly across the fragment. Once the parchment is nearly dry, the clips are removed and the fragment is placed between felts and under light weight to complete the drying process.

Kathryn Kenney tensioning a parchment manuscript fragment using clips and pins. Photo credit Cathie Magee .

Kathryn Kenney tensioning a parchment manuscript fragment using clips and pins. Photo credit Cathie Magee , 2021.

Parchment manuscript fragment drying under tension using clips and pins. Photo credit Kathryn Kenney .

Parchment manuscript fragment drying under tension using clips and pins. Photo credit Kathryn Kenney, 2021 .

Side vie of parchment manuscript fragment drying under tension using clips and pins. Photo credit Kathryn Kenney .

Side vie of parchment manuscript fragment drying under tension using clips and pins. Photo credit Kathryn Kenney, 2021 .

• Flattening under tension: Rare earth magnets
This method was very useful for fragments with creases near tears or other areas of vulnerability. For fragments where drying under tension with clips and pins was not possible due to tears in the parchment, we used the strength of rare earth magnets to hold the parchment in place while drying. Cathie wrapped small rare earth magnets in soft linen tape. We placed the humidified parchment fragment on a piece of polyester webbing over a flat metal sheet. The rare earth magnets were carefully positioned to apply light tension to flatten the humidified creases. Once the parchment was nearly dry, the magnets were removed and the fragments were placed between felts and under light weight to complete the drying process.

Parchment manuscript fragment drying under tension using rare earth magnets with a diameter of ½”. Photo credit Kathryn Kenney.

Parchment manuscript fragment drying under tension using rare earth magnets with a diameter of ½”. Photo credit Kathryn Kenney, 2021.

Detail of a parchment manuscript fragment drying under tension using rare earth magnets. Photo credit Kathryn Kenney.

Detail of a parchment manuscript fragment drying under tension using rare earth magnets. Photo credit Kathryn Kenney, 2021.

Mending

These fragments are teaching tools that will be used to illustrate the use and re-use of parchment manuscript fragments over time. Because that evidence of previous use is important, many of the tears and losses in these fragments were not repaired. I chose to mend tears and losses only where they posed a risk for handling. In areas where I chose to apply mends, I used alum-tawed goldbeater’s skin. Since parchment is a highly hygroscopic material, I wanted to use a mending material that would respond similarly to environmental changes. The goldbeater’s skin is also an animal product, and is thin and flexible but very strong. I toned the material lightly with washes of Golden acrylic paint and used gelatin to adhere the mends to the parchment. The mends are very minimal but will help support and protect these fragments during use. Once mended, the fragments were housed in individual polyester film sleeves.

Conclusion

This project was so much fun to work on. I was able to learn quite a few new techniques and benefit from the expertise of the conservators at the Library of Congress. The collection now has a robust description and is ready to be used as a teaching tool in the Rare Book and Special Collections Division. I enjoyed the opportunity to work with this unique collection that highlights the use and reuse of these materials over time, using the current condition to reconstruct the history of each fragment, and exploring new treatment and photography methods.

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