A step forward in disclosing the secret of stradivari's varnish by NMR spectroscopy

Abstract

It is commonly thought that the varnishes used by the great violin-maker Antonio Stradivari may have a role in determining not only the esthetical features but also the acoustic properties of his instruments, and the idea of a "lost secret" is still widespread among musicians and violin-makers. Previous scientific researches on varnish samples of Stradivari's instruments revealed that they were generally made by a mix of linseed oil with and colophony or metal rosinates in different ratios ranging between 75/25 (oil/resin) and 60/40 (oil/rosinate). However, it is still not clear whether the mixture composition can be related to any structural and/or functional feature of the resulting varnish. To investigate this aspect, we prepared varnishes with different linseed oil/colophony (w/w) ratios and applied NMR techniques to achieve information about their chemicalphysical characteristics. Here, we show that the two components strongly interact in the solid state and that only the varnish prepared from 75/25 (w/w) linseed oil/colophony mixture displays unique properties in terms of dynamic homogeneity unlike coatings with other compositions. Our results suggest that the so-called "secret" of Stradivari's finish could not be related to unknown ingredient(s) but to a specific oil/resin composition that provides the best performance.

CHEMICAL COMPOSTION OF TAURUS FIR (Abies cilicica subsp. isaurica) OLEORESIN

“…It is known that abietic acid has a lipoxygenase activity, possessed anti-inflammatory properties and binds to phospholipids bilayer (Yadav et al, 2016). Also, it has a positive effect on the acoustic properties of violens (Spinella et al, 2017). As abietic acid itself is known to be non-allergenic or weak allergen, some of the oxidation products such as 7-oxodehydroabietic acid have major contact allergens.…”

“…Derivatives of colophony are used in cosmetics and dental varnishes (Yadav et al, 2016). Also, musicians and baseball pitchers uses colophony (Spinella et al, 2017). China, Brazil, Indonesia, Portugal are the big gum rosin producers (Karlberg, 2012, Serin Odabas et al, 2014.…”

Violin varnish induced changes in the vibro-mechanical properties of spruce and maple wood

“…The (tacit) knowledge about the varnish procedure of the renowned Cremonese violin makers, however, was not continuously handed down and got lost over the years (Cattani et al 2013). Therefore, most studies focus on revealing the varnish compositions and the preparation methods used by the famous luthiers (Echard and Lavedrine 2008;Echard et al 2010;Bucur 2016;Spinella et al 2017;Fiocco et al 2019).…”

Effect of coating systems as a barrier to humidity for lutherie woods studied by neutron radiography

“…A full understanding of the complex geometry, structure and material composition of violins, resulting from the treatments described above, is still lacking. Previous studies have focused on the varnish characterisation through micro-analytical techniques [10][11][12][13][14][15], characterisation of the material components [16], and acoustics [17,18]. The techniques used to date, are superficial or micro-destructive.…”