Nondestructive observation of multilayered modern paintings by electromagnetic waves

Electromagnetic waves from microwave to X-ray have been used in heritage science research filed. We have examined masterpieces of modern paintings among collections of the Ikeda Museum of 20th Century Art in Japan, by using THz time-domain imaging, near-infrared camera, and X-ray fluorescence, depending on the points to be discussed. An oil painting by Salvador Dali has been mounted on aluminium plate for conservation purpose in the 20th century. THz imaging revealed multiple painting layers and thick supporting layers on the aluminium plate. Infrared imaging of a gouache painting by Marc Chagall clearly shows underdrawings. X-ray fluorescence method is applied to investigate paints used by Joan Miro, and successfully distinguished two white pigments.