Science used to reveal masterpiece's true colors: Chemist uncovers paint details of Renoir masterpiece at Art Institute of Chicago

Northwestern University chemist Richard P. Van Duyne, in collaboration with conservation scientists at the Art Institute of Chicago, has been using a scientific method he discovered nearly four decades ago to investigate masterpieces by Pierre-Auguste Renoir, Winslow Homer and Mary Cassatt.

Van Duyne recently identified the chemical components of paint, now partially faded, used by Renoir in his oil painting "Madame Léon Clapisson." Van Duyne discovered the artist used carmine lake, a brilliant but light-sensitive red pigment, on this colorful canvas. The scientific investigation is the cornerstone of a new exhibition at the Art Institute of Chicago.

Van Duyne will discuss his research on Renoir's painting as well as his studies of Winslow Homer's watercolor "For to be a Farmer's Boy" and Mary Cassatt's pastel "Sketch of Margaret Sloane, Looking Right"at a Feb. 13 press briefing at the American Association for the Advancement of Science (AAAS) annual meeting in Chicago. The briefing, "Paintings: At and Under the Surface," will be held at 10 a.m. CST in Vevey Room 3 of the Swissôtel Chicago.

Van Duyne also will speak about "Detecting Organic Dyestuffs in Art with Surface-Enhanced Raman Spectroscopy" Friday, Feb. 14, at the AAAS meeting.

To see what the naked eye cannot see, Van Duyne used surface-enhanced Raman spectroscopy (SERS) to uncover details of Renoir's paint. SERS, discovered by Van Duyne in 1977, is widely recognized as the most sensitive form of spectroscopy capable of identifying molecules.

The show runs Feb. 12 through April 27 at the Art Institute of Chicago, 111 S. Michigan Ave. More information is available at http://www.artic.edu/exhibition/renoir-s-true-colors-science-solves-mystery.