Invited Paper CS-ThM5
Advanced Spectroscopy for Traditional and Modern Heritage Materials

Thursday, November 13, 2014, 9:20 am, Room 313

The conservation of art and cultural heritage objects requires advances in non-invasive, non-destructive analytical techniques to characterize cultural heritage materials, including substrates (paper, parchment) and media (inks, pigments, colorants). Spectral imaging systems developed for astronomical imaging and remote sensing have been adapted and customized for libraries and museums. T he Library of Congress LC) is using hyperspectral imaging to support preservation of cultural heritage materials with a range of capabilities. With an integrated 39 MegaPixel camera and LED illumination panels to capture high-resolution images in ultraviolet, visible and near infrared spectrum, researchers can create a spectral map of a manuscript or object that can be linked with other non-invasive analyses. Hyperspectral imaging captures non-visible and visible information in registered high resolution digital images, with further capabilities including identification of materials through spectral response, and monitoring of degradation or changes due to environmental conditions and conservation treatments.

The Library utilizes this system to address challenges associated with characterizing manuscript materials, including: early Portolan (nautical) Charts, L’Enfant Plan of Washington D.C., Jefferson’s handwritten draft of the Declaration of Independence, and Herblock political cartoons. It has been used to illustrate non-invasive characterization of materials, deterioration, and detection of non-visible changes due to exhibition and storage. Assessing the long-term effects of treatments on collection materials is a growing area of research at LC. The conservation of a 1513 hand-colored Ptolemy Geographia posed interesting challenges in terms of the treatment of select maps in poor condition, due to the presence of verdigris, and a later restoration treatment. Analysis for treatment to stabilize these seven maps included a combination of quantitative X-ray fluorescence, spectral imaging, and Raman spectroscopy. Development of reference databases and integration of data from other analytical techniques allows a more complete mapping of collection materials. Linking this mapping data with other spectroscopic techniques allows for more data from single-point analyses, and provides a greater depth of information. Scriptospatial mapping of data enables direct sharing and visualization of data, with capture of standardized instrumentation parameters and object metadata. The scriptospatial interface enhances interaction between a range of professions, allowing multidisciplinary collaboration for integration of preservation, scientific and cultural information.