The artistic scene in sixteenth-century Milan was incredibly dynamic and active, and a key figure of the period was the Milanese painter Giovanni (Gian) Paolo Lomazzo. His writings (the famous Trattato, the shorter Idea del Tempio della Pittura, as well as the more obscure Libro de’ Sogni and the peculiar Rabisch) represent a valuable source of information to investigate the type of knowledge Milanese artists were expected to acquire, what texts and authors they were aware of (either directly or indirectly), and how they shared this knowledge among themselves. Artist and academician Lomazzo reflects the tendency of sixteenth-century artists to consider practical and theoretical knowledge both complementary and necessary for painters, and his activities in the Accademia de la Val di Blenio testify to his ambition to gain a reputation beyond that of a painter. His interactions with other figures belonging to the intellectual life of the city: Bernardino Baldini, Guido Mazzenta, and Girolamo Cardano, to mention but a few, demonstrate the wide range of his interests. Lomazzo constitutes an exemplary case of the intellectualization of the artist’s profession, in which reading and referring to texts became an increasingly important element of the painter’s job during this period.