Writing for the online magazine Ludwig van Toronto, Anya Wassenberg summarizes research by an Italian team into the coating and varnish applied to the classic violins made by Antonio Stradivari. The treatment of wood that produces the remarkable sound of these instruments has been one of music’s enduring mysteries.
Chemically analyzing samples from two Stradivari instruments, the Toscano of 1690 and the San Lorenzo of 1718, the researchers identified a layer of protein coating, perhaps an animal-based glue, between the wood and an exterior layer of varnish. The coating and varnish mixed with each other and with the wood after application.
“The system of applying the coatings was complex, and involved extremely thin layers of a few micrometers each,” Wassenberg writes.
Her article, with a link to the study, published by the American Chemical Society: