Non-invasive mobile technology to study the stratigraphy of ancient Cremonese violins: OCT, NMR-MOUSE, XRF and reflection FT-IR spectroscopy

Reflection FTIR spectroscopy for the study of historical bowed string instruments: Invasive and non-invasive approaches

“…Bands related to a proteinaceous material -such as animal glue or casein -at 1650 cm -1 (vC=O, amide I) and 1550 cm -1 (combination of vC-N and δN-H, amide II) [54,55] characterize all the KKT spectra collected on layer B (Figure 2, c). These results turned out to be in accordance with the non-invasive FTIR investigation performed on the backplate of the Bracco 1793 small violin [56] ( Figure 3, a,b). In addition, some inorganic phases are mainly detected by the non-invasive analysis on the most worn-out areas of the Bracco: the Reststrahlen bands at around 1100-1000 cm -1 (v as Si-O-Si) as well as the signals at 1150 and 1100 cm -1 (v as SO 4 ), together with those at 670 and 600 cm -1 (δ as SO 4 ), can be attributed, respectively, to the silicate and sulphate groups [57,58].…”

“…Also in these cases, the maximum value for the band at 1710 cm -1 is observed in the area corresponding to the varnish layer A (Figure 4, b1) and the proteinaceous material is mainly assigned to the preparation layer B, but it also extended up to the lower portion of the varnish layer A ( Figure SM3b). It is worth reporting that, as already shown in [56], some signals of proteinaceous material were also found through a non-invasive approach in well-preserved areas of the Bracco small violin, thus suggesting the presence of restoration materials in the most external layer of the coating system. A similar picture emerges by considering the multivariate scores maps (Figure 4, a2-c2).…”

Surfing through the coating system of historic bowed instruments: a spectroscopic perspective

“…The presence of iron, identified both with XRF and EDX, was instead attributed to iron earth particles, possibly added as pigments. 6,15…”

String Theories: Chemical Secrets of Italian Violins and Chinese Guqins

“…Only a brief account will be given here. Joseph Michelman [10] , Pollens [11] , and Padding [12] , as well as articles by Echard [13,14] and Fiocco [15,16] . Based on decades of research, we finally have a basic understanding of the stratigraphy and composition of Stradivari's varnish.…”