Application of THz sensing to analysis of works of art for conservation

Terahertz (THz) spectroscopy and THz imaging techniques are expected to have great potential for the noninvasive analysis of works of art. THz waves can penetrate opaque materials and have the potential to non-destructively create three-dimensional maps of materials by spectroscopic imaging. Satisfactory results using model samples have been obtained by many institutions. We have succeeded in the first ever noninvasive cross-sectional imaging of a tempera masterpiece by Giotto, which revealed that the artwork was painted by the medieval technique. Moreover, the material mapping of an east Asian mural painting revealed that two materials were used to make the same colour. These examples prove that THz technology is of great practical use for art conservation science.