To most of us, looking at the finish of an antique musical instrument conjures the image of painstaking, fine craftsmanship. Thanks to 3D scanning, scientists at several universities in Italy have been able to delve into the details of the multi-layered coating methods that gave antique violins their handcrafted look.
In a study published in EPJ Plus, Giacomo Fiocco, affiliated with both Pavia and Torino Universities in Italy, and his colleagues used the synchrotron facility in Treiste to develop a non-invasive 3D-scanning approach that provides details on the main morphological features of the overlapping finishing layers used in violins. These images, in turn, can be used to determine the coating’s chemical nature, which scientists hope can help rediscover the procedures and materials used to hopefully reproduce the multi-layered coating methods.
In this study, the authors rely on a 3D scanning method, called Synchrotron Radiation micro-Computed Tomography (SR-micro-CT). Moreover, they employ the Elettra Synchrotron Trieste synchrotron, a beam of accelerated particles that produces a high flux of radiation spread over a continuous spectrum extending from infrared to hard X-rays.
The authors first use the X-ray beam to scan two sets of mock-ups, which were prepared in their lab to mimic the finishing layers on the historical instruments. Using the mock-ups, they then optimize the 3D scanning settings, boost the spatial resolution, and define the parameters required for 3D reconstruction. The authors then focus on a large fragment removed from a damaged cello made by the 17th-century Italian luthier Andrea Guarneri. Lastly, they compare their findings with those produced by micro-invasive analyses of the varnish to evaluate the merits of the reconstructed volumes and virtual slicing in terms of investigating such layered, complex structures.