Identifying the composition of pigments in century-old artworks could be made easier soon, with the discovery of a new technology called photoacoustic infrared spectroscopy.

The chemical composition of pigments is important to know, because it enables museums and restorers to know how the paints will react to sunlight and temperature changes, so that adequate preservation techniques can be employed.

Dr. Ian Butler at McGill's Department of Chemistry used the new technique, which is based on Alexander Graham Bell's 1880 discovery that showed solids could emit sounds when exposed to sunlight, infrared radiation or ultraviolet radiation, to analyze typical inorganic pigments that most artists use.

The researchers have classified 12 historically prominent pigments by the infrared spectra they exhibit - i.e., the range of noises they produce - and they hope the technique will be used to establish a pigment database.

"Once such a database has been established, the technique may become routine in the arsenal of art forensic laboratories," said Butler. (ANI)