Der Heilige Lukas, die Madonna malend

According to legend, Luke the Evangelist was a doctor and painter; in a vision he is said to have seen the Blessed Virgin and Child and to have captured them in a painting. Thus he is considered the patron saint of painters. Petrini, a protagonist of the 'Settecento Lombardo', was active in Lombardy, often in Valtellina, Ticino and Piedmont. His style is characterized by a strong sculptural presence, by simplification of form and light. With the plaster mask hanging on the wall in the background, an art theoretical reflection on the nature of painting in comparison to sculpture comes into the picture. Source