Manuscript materials from the Middle Ages and Renaissance encompass a variety of formats including bound volumes, letters, legal documents, calligraphic samples, and maps. The manuscripts themselves were written on paper or parchment, although associated bindings may have been in paper, leather, or vellum. While some documents may be written with pigments or gouache, during the late Middle Ages iron gall ink began to be widely used for handwritten documents as well as for artist’s drawings. Its indelibility also made it desirable for official legal records.

The preservation of early manuscripts requires consideration of their material composition. A stable storage environment is one of the most important factors in securing their longevity. The optimal environment will be a relatively constant temperature and humidity with very little fluctuation (Newberry Library conditions: 65 degrees Fahrenheit, 45 % Relative Humidity +/- 5%). Additionally, because the damaging effects of light are cumulative, light exposure should be minimized for these materials.

Manuscripts of this time period may exhibit preservation issues from years of handling and/ or improper storage. Some damage or degradation such as iron gall ink corrosion may require professional conservation treatment to prolong the life of the item. Other common preservation issues include tightly folded documents, planar distortion of parchment or paper, physical damage, restrictive openings of book bindings, flaking pigments.

Materials that were digitized in this website project were first reviewed by a conservator to identify preservation issues that would require treatment before their digitization. For example, folded documents required unfolding prior to digital capture. Documents and letters that have been folded for hundreds of years are not easy to unfold and may be damaged if attempts are made. In the case of these manuscripts, careful humidification and flattening was performed by a conservator. Parchment materials, which are extremely hygroscopic, were examined for planar distortions. Distortions not only create issues for digital capture, they present serious preservation concerns for the conservator. Undulations in the page may result in flaking, loss, or lifting of the pigments used for writing. In such cases a conservator, working under a microscope, would perform time-consuming consolidation of the pigments. In addition to conservation of fragile materials prior to digitization, conservators worked with digitization staff to provide the best possible support for the bound codices to reduce stress on bindings during image capture.

Because even the least invasive conservation treatment alters the original manuscript, preventing deterioration of early manuscripts must be of utmost priority to the researcher as well the institutional depository. Proper storage for these materials as well as gentle handling by researchers will help to ensure these primary sources are preserved for future generations of scholars.

For more about preservation, see the website of the American Institute for Conservation of Historic and Artistic Works.

Lesa Dowd
Director, Conservation Services
The Newberry Library