The Identification of Pigments through Non-Invasive Spectroscopic Analyses: the Bernardino Luini Frescoes of Santuario della Beata Vergine dei Miracoli in Saronno (Italy) as a Case Study

It is well known that the painting technique of the great Leonardo da Vinci heavily affected many notable artists of his age. Among them there was Bernardino Luini, who was one of the most important Italian masters that worked between the 15th and 16th centuries. In this research paper, the first results of the analytical survey made on two of the numerous wall paintings present in the Santuario della Beata Vergine dei Miracoli in Saronno (Italy) are shown. In detail, the “Marriage of the Virgin and the Adoration of the Christ Childmade” by Luini (Figure 1) and the “Adoration of the Christ Child” (which is suspected to be a Luini as well) were analysed in a totally non-destructive manner in order to compare the colour palettes utilised for their creation and to possibly help with the attribution of the latter. The multi-analytical spectroscopic study was performed by portable X-ray fluorescence (XRF), Fourier transform infrared reflection (R-FTIR) spectroscopy, Raman spectroscopy and visible reflectance spectroscopy. It permitted the identification of the majority of pigments of both paintings and the presence of some retouches and degradation products. The research is ongoing and will be completed with the application of some imaging techniques, such as hyperspectral imaging, to obtain the distribution of the different colours and restoration areas on the two wide painted surfaces.