Fenella G. France: Advanced non-invasive spectral preservation at the Library of Congress.

An ongoing challenge associated with the conservation of cultural heritage is the need for advances in non-invasive, non-destructive analytical techniques that can be used to characterize manuscripts 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. The Library of Congress has been developing the application of hyperspectral imaging to the preservation of cultural heritage materials as a powerful, non-invasive technique for assessing manuscripts. Advanced imaging allows non-invasive characterization of materials, providing both access and enhanced non-visible and visible information in registered high resolution digital images.

This non-contact tool has the capacity to non-invasively identify and characterize colorants, inks and substrates through their spectral response, monitor deterioration or changes in parchment and paper due to exhibit and other environmental conditions, and assess previous treatments that modify chemical and spectral responses of cultural heritage materials. The resulting cube of data creates a new "digital cultural object" - related to, but distinct from the original.

A range of case studies will be utilized to discuss the challenges associated with characterizing manuscript materials. These will include Portolan Charts, L'Enfant Plan of Washington D.C., Jefferson's handwritten draft of the Declaration of Independence, James Madison debate papers, and other manuscripts illustrating non-invasive characterization materials, deterioration, and detection of non-visible changes due to exhibition and storage.

The imaging program includes the development of a spectral reference database, and the integration of data from other non-invasive analytical techniques, to create a full analytical mapping of objects for non-destructive analyses of collection materials.