Two stucco sculptures from the “Salone d'Ercole” in the Racconigi Castle (Cuneo, Italy): a case study

Non-invasive and micro-destructive diagnostic investigations were employed for the study of two stucco statues depicting Putti, from the “Salone d’Ercole” in the Racconigi Castle (Cuneo, Italy). The research made it possible to understand the construction technique, constituent materials, and the state of conservation of the statues. This information was useful for placing the artworks in the correct historical-artistic context and for conservation choices and restoration interventions. Different analytical investigations were applied, specifically: a) the internal metal structure was analyzed by cover meter relief combined with digital radiographic technique; b) the stucco composition and its stratigraphy were characterized by Polarized Optical Microscopy (POM), X-ray diffraction (XRD) and Electron Scanning Microscopy coupled with Energy- Dispersive X-ray spectroscopy (SEM-EDX); c) finally, the presence of organic compounds was observed by UV-Induced Visible Fluorescence (UVL) and then characterized by Fourier Transform Infrared Spectroscopy (FT-IR) analyses. The results show that the stucco Putti were made with the techniques and raw materials widely used by Ticino artists and plasterers’ workshops active between the 16th and 17th centuries, in the current Canton Ticino region. As regards the state of conservation, decay phenomena such as exfoliation and loss of material were mainly attributable to the presence of epsomite.