Every year the Preservation Directorate of the Library of Congress participates in American Library Association’s Preservation Week. This annual celebration highlights preservation efforts in libraries, archives, museums, historical societies and collecting institutions in communities all across the country.
Fenella France, Chief of the Library’s Preservation Research and Testing Division (PRTD), started out Preservation Week with a heritage science introduction to the world of fragments. Although fragments have been largely dismissed by scholars in the past, collections of fragments actually represent a largely untapped source of research topics and teaching opportunities. Often the chemical characterization of a parchment, as well as any inks and pigments present, provides far reaching information, from the practical knowledge of how to stabilize and preserve, to answering curatorial questions, such as construction techniques or geo-sourcing of materials, to expanding scientific knowledge on the physical and material characteristics of aged materials and their degradation. Take a closer look at how research science informs preservation here.
Working closely with Rare Books and Special Collections Division, PRTD has been studying 12th to 16th century parchment fragments using an array of non-invasive and portable equipment. These fragments come from various places around the world, providing PRTD with a range of material aspects to study. Fenella’s team start their study of fragments with multi-spectral imaging and build on the knowledge using a variety of analytical techniques, including X-ray fluorescence spectroscopy (XRF), Fourier-transform infrared spectroscopy (FTIR), fiber optic reflectance spectroscopy (FORS), volatiles profiling, parchment speciation, 3D mapping, and more!
Here’s a snapshot of Fenella’s team at work.
Meghan Wilson and Chris Bolser work on the multispectral imaging system, taking specialized images and employing various processing techniques. Multispectral image cubes are generated by illuminating the parchment fragments at different wavelengths and can reveal hidden or obscured text, construction techniques, and highlight the location of different materials across the page. From this overview of the document, other complimentary techniques are employed to dive deeper into the mysteries of the fragment.
Tana Villafana, Hadley Johnson, and Cindy Connelly Ryan are shown performing FORS, FTIR, and XRF, respectively. Each technique works together to prove a fuller understanding of the materials. For example, XRF can identify heavy metals, such as lead, and FORS can confirm the pigment as red lead. FTIR provides information on binding material and, suddenly, we know a lot about how a particular paint came to be on a fragment. What’s more, ancillary minerals can be identified using XRF, leading to the possibility of geo-sourcing the very origin of the materials on these century old fragments.
Another unique way of examining these fragments is through the capture volatile organic compounds (VOCs) and 3D scanning. In the image above, Kelli Stoneburner captures the VOCs that are being released by the fragment, later to be analyzed through a gas chromatography mass spectrometer. These analyses can tell us a lot about the current state of degradation of an object. Eric Monroe is shown with a 3D scanner, digitally scanning the fragment to create a three-dimensional model to allow for surface and thickness measurements without having to disturb the object.
All Preservation Week webinars, including Fenella’s, will be located at the link below, so keep clicking!
Of course, these aren’t the only scientists in the PRTD labs and they do a lot more than Fragmentology! Check out these blogs for a peak into the world of the Library’s scientific material research.