Chemical clues to the mystery of what's coating Stradivari's violins

Stradivarius violins produce elegant music with a level of clarity that is unparalleled by modern instruments, according to some musicians. And it's the finishing touches -- mysterious treatments applied hundreds of years ago by Antonio Stradivari -- that contribute to their unique look and sound. In a step toward unraveling the secret, researchers report on a nanometer-scale imaging of two of Stradivari's violins, revealing a protein-based layer between the wood and varnish.