New insights on the painting "Portrait of Mario Nuzzi": a preliminary analytical study of Mario Nuzzi's pictorial production and of his artistic collaborations

The study and characterization of an art work carried out by two or more artists is always an interesting challenge since each painter, although belonging to the same artistic current, can introduce specific pictorial materials or peculiar aesthetic effects, which constitute the artist fingerprint. This work presents a preliminary analytical study of the "Portrait of Mario Nuzzi", painted by Giovanni Maria Morandi and Mario Nuzzi. In particular, non-invasive investigations were conducted using UV–VIS–NIR–SWIR multispectral imaging, radiography and X-ray spectroscopy (XRF). Multivariate analyses (PCA) were performed on VIS–NIR multispectral imaging in order to highlight some details not clearly visible using a traditional univariate analysis. Such an approach could be useful for authentication processes. In particular, in this paper we propose the use of the score density plot to determine the artist's "chiaroscuro" fingerprint. Finally, the artist's palette was compared with that of the "Primavera" painting, painted by Mario Nuzzi and Filippo Lauri, by using XRF analyses. We discovered that "Portrait of Mario Nuzzi" has not been significantly changed since the final version. Furthermore, the elemental composition of the pigments revealed that the palette used in the two paintings does not completely overlap. This aspect encourages us to perform a more detailed analysis of the pigments with the aim of better discriminating the parts painted by Mario Nuzzi from those of each collaborator.