Technical peculiarities in Giovanni Santi’s paintings on canvas

Giovanni Santi (Colbordolo ca. 1439–Urbino 1494) was one of the most important painters active in Urbino (Marche region, Italy) during the last decades of the fifteenth century, where he was employed at the court of the celebrated Federico da Montefeltro. He is known mainly as the father of Raphael, but he had a remarkable production of paintings, especially on wood but also on canvas and on wall. This paper focuses on technical peculiarities related to Santi’s paintings on canvas, including some practices that have not yet been noted in relation to his panel paintings. In particular, two works painted on herringbone-weave linen canvases were investigated: Tobias and the Archangel Raphael and Saint Roch (both dated ca. 1490–94), in the collection of the Galleria Nazionale delle Marche. The results presented are a part of a large research project based on noninvasive and micro-invasive investigations carried out on twenty-eight works attributed to Giovanni Santi, only partially published in a recent exhibition catalog dedicated to the artist (Palazzo Ducale, Urbino, 2018). Black underdrawing, characterized by a thinly applied network of close hatching for some of the shadows, was observed and, regarding the different hues, a complex use of pigments. The binder detected is siccative oil, with the addition of a large amount of transparent glass particles, which would have been added both to give body to the pigment without using white fillers and to improve drying, a technique that Santi presumably learned from the Flemish painter Justus van Ghent (act. Urbino ca. 1473–1475) and something that he possibly transmitted to his son Raphael as a workshop practice. In fact, Giovanni Santi’s workshop survived his death.