Terahertz imaging for analysis of historic paintings and manuscripts

Through the application of terahertz spectroscopy and imaging to the analysis of art, we have developed a spectral database of art materials containing more than 200 spectra of various pigments and binders. With this database, a red ink used in a thirteenth-century manuscript was identified; the results were verified by X-ray fluorescence elements mapping. Terahertz transmission spectral component analysis successfully distinguished stains on the red ink. Reflection imaging also can be used to distinguish materials. Similar techniques can be applied to construct images of specific materials on objects not only in art conservation science but also in various other industries.