Mid-wave Infrared Reflectography and Thermography for the Study of Ancient Books: A Review

ABSTRACTIn this paper an overview of recent applications of mid-wave infrared imaging techniques to the study of books is presented. Studies performed by thermography and mid-wave infrared reflectography are reviewed to demonstrate how they can be used to investigate the main features of books. The capability of these techniques is exploited in the analysis of structural elements of the bookbindings and writing supports as well as in the characterization of the writings and illuminations. Thermographic and reflectographic results are compared with results obtained using other imaging techniques operating in different spectral regions, thus pointing out how mid-wave infrared imaging techniques can help in examining many aspects of books. Finally, it is shown that the obtained information can also be used to evaluate the condition of the book and, when required, to properly plan conservation treatments.