Glass materials let Venetian art shine.

Sixteenth-century Venetian painters, renowned for their brilliant and colorful works of art, may have borrowed a few tricks from an unlikely source: glassmaking. Recent analyses of several Venetian paintings reveal that the artists mixed glassy particles into their oil paints, perhaps in an effort to expand their palettes and enhance the vibrancy of their colors.

"The glassmaking industry was burgeoning in Venice at the time,' says Barbara Berrie, a conservation scientist at the National Gallery of Art in Washington, D.C. While scanning a 1543 inventory from a Venetian store that sold paint pigments, Berrie discovered a number of materials necessary for making glass. She then analyzed several Venetian paintings to see whether she could find similar materials. Using scanning electron microscopy and other analytical techniques, Berrie examined a sample taken from Lorenzo Lotto's 1522 painting St. Catherine. She found microscopic particles of pure silica--one of the main components of glass. Analyses of Tintoretto's Christ at the Sea of Galilee disclosed transparent green particles with a chemical composition very similar to that of blue smalt, a cobalt-containing glass material. And in Raphael's Alba Madonna, Berrie found lead silicate, a yellow glass made by master glassmakers at the time.

Berry suspects that Venetian artists were attracted to the way the glassy additives made the colors in their paintings seem more luminous.--A.G.