Art

Infrared light can reveal techniques and materials used by Renaissance artists like Leonardo Di Vinci.

Uncovering the underdrawing in Raphael's Madonna

Underdrawings are drawings that Renaissance artists like Leonardo Di Vinci, Raphael, and Bruegel did before applying paint to their masterpieces. Many have been detected using infrared imaging. They provide insight into the techniques and materials used by these celebrated artists, and are of great historic value.

Raphael was known to make underdrawings on paper. He would prick the underdrawing with a pin to make an outline of it, and place it on top of one of the primed, white, wooden panels on which he preferred to paint. Next he would transfer the outline of the underdrawing to the panel, by dusting the pinpricks he had made with charcoal.

Most paints are transparent in the infrared, but charcoal is not. The charcoal outlines of many of the underdrawings that Raphael made for his masterpieces, such as Procession to Calvary and Madonna of the Pinks, have been revealed using infrared imaging.