BACKGROUND
Through measurement of the spectrum of laser light scattered from selected microscopic regions of a document or manuscript, Raman spectroscopy provides a powerful non-destructive methodology for characterizing the chemical composition of inks and pigments.
Columbia University’s Rare Book and Manuscript Library houses one of the largest collections of ancient papyri in North America containing over 2150 papyri dating from the 3rd century BCE to the 7th century CE. In addition to this collection, the library houses many ostraca and numerous additional ancient documents and manuscripts. In 2012, we established a team for a collaborative venture to explore the inks of selected papyri and other materials from the Columbia collection. This initial team consisted of (1) Alexis Hagadorn, Head of Conservation, Columbia University Libraries, (2) Dr. David Ratzan, Former Curator of the Papyri Collection and Head of the Library at NYU’s Institute for the Study of the Ancient World (ISAW), (3) Prof. James Yardley, Managing Director of the Columbia Nanoscale Science and Engineering Center, along with (4) Prof. Roger Bagnall, Director of the Institute for the Study of the Ancient World (ISAW).
The Ancient Ink Laboratory has developed a comprehensive program to explore the nature of the inks used to create Egyptian papyri and other ancient documents. These explorations include the use of Raman spectroscopy to evaluate the chemical nature of the pigments or dyes used. We pay special attention to black inks, most of which are based on carbon. By examining carefully the Raman spectra for these carbon-based inks we can learn much about the nature of these inks – how the pigments were made and how the inks were prepared. We also observed systematic changes in the observed spectra with the age of the document. This latter may ultimately provide a useful means for dating for some manuscripts. We established a capability to prepare modern inks based on ancient methodology and on modern carbon-based pigments and for quantitatively studying the aging processes. We also explored the evolution of red inks in antiquity and studied polychromatic manuscripts including a fragment from the Egyptian Book of the Dead.