The northern-Italy Renaissance in a panel by Defendente Ferrari: A complete study with a multi-analytical investigation

Defendente Ferrari, one of the most important painters of the Piedmontese Renaissance, was extremely active in the early 16th century. His Madonna with Child and two Saints (1505-1510 ca.), which was originally located in the Collegiate Church of Carmagnola (Turin province, Italy) now in the collections of Palazzo Madama -Museo Civico d'Arte Antica in Turin, was recently analyzed and restored at the Centro Conservazione e Restauro La Venaria Reale, as part of a study and conservation project focused on the artist and his circle. This study presents an interdisciplinary and multi-analytical archaeometric approach resulting from the collaboration of several universities and research centers. The adopted protocol allowed for clarifying some peculiarities of the artist's painting technique, such as the use of the dotted -a technique applied to render the nuances, volume, and flesh tones of the figures -and that of thin black cross-hatched strokes, drawn to shape the clothes and to define the related volumes and folds. Moreover, specific degradation processes were studied, which apparently occur also in other contemporary artworks with similar features. Of particular interest is the alteration of the blue color of the Virgin's garment, made of azurite and presently strongly blackened. SWIR reflectography performed with a high-resolution InGaAs scanner prototype allowed for imaging both the detailed underdrawing and the careful hatching used to highlight the shadows. The combined application of optical microscopy, SEM-EDS, mu-Raman, FT-IR spectroscopy, and GC-MS has been fundamental for analyzing some specific pigments, binders, and varnishes, as well as for inferring the cause for Virgin's garment blackening. A complete mapping of the pigments was provided through the combination of FORS (350-2000 nm), portable mu-Raman, MA-XRF, and Hypercolorimetric Multispectral Imaging. The latter also allowed for observing the distribution of what is supposed to be either the original or the ancient organic finishing layer, which was maintained during the conservation treatment. This research has brought to an in-depth knowledge of the artist's painting technique and helped the adoption of the best choices for an effective and minimal-invasive restoration intervention.