A Stradivarius is among the most coveted items in the world, considered to be the best-stringed instrument ever created. The violins, violas and cellos produced by the Stradivari family during the 17th and 18th centuries are prized for their remarkable sound and incredible craftsmanship, and a new study explores the possible techniques used by Antonio Stradivari.

A Stradivarius in pristine condition can fetch millions of dollars. In 2011, a Stradivarius violin made in 1721, named Lady Blunt after Lord Byron’s granddaughter, Lady Ann Blunt, was sold at a charity auction for $15.9 million. The money collected during the auction went to Japanese earthquake relief funds.

Approximately 600 string instruments made by Stradivari are still known to exist, according to the Wall Street Journal, and a new study using several diagnostic techniques examined a Stradivarius to unlock the mystery of what techniques and materials were used to create the world’s best violins.

Led by Marco Malagodi, from the Università degli Studi di Pavia in Italy, the study used different techniques to examine the wood, types of varnishes used and decorations of the top plate of a 17th-century Stradivarius. The techniques were nondestructive, and the researchers were able to discover what dyes were used in the making of the violin, as well as noting the lack of varnish on the top plate, a result of excessive restoration, the press release notes. The researchers were able to identify the type of dye used in the purflings, the decorative edge inlay found on the top plate, while also identifying other aspects of the wood that indicate Stradivari used ancient wood coloring techniques, according to the release. The study was published in the journal Applied Physics A - Materials Science & Processing.

“Our investigations have provided several important insights about the manufacturing techniques of Antonio Stradivari and allowed us to hypothesize about the recipes used by this violin master, or by his suppliers, to decorate his instruments,” the study notes. While the researchers may have been able to unlock some mysteries surrounding the techniques used by Stradivari, previous studies have dispelled some of the myths surround the legend of the violin. Past research has concluded that most cannot tell the difference between a Stradivarius and a high-quality modern violin, but that has done little to dispel the legacy of Stradivari, the craftsmanship of his stringed instruments or the incredible prices they fetch.