A non-destructive imaging technique used to detect the presence of specific pigments in a painting. Infrared light is directed at the painting and an infrared camera captures the light reflecting back. The resulting image is converted digitally, producing a black-and-white image on a computer monitor. Infrared reflectography allows curators, conservators and art historians to “see through” paint layers to detect underdrawings, pentimenti, retouchings, signatures and dates.

Curator using infrared reflectography to examine a painting. Photo: Yale Center for British Art, New Haven, Conn.