«Di gratia, dichiararsi di ogni soggetto la sua particolarità». Il perduto trattato sulla pittura di Giuseppe Valeriano e il ms. Ges.688 della Biblioteca Nazionale Centrale “Vittorio Emanuele II” di Roma

The article centers on an unpublished 16th-century treatise on painting by a Jesuit artist discovered by the author in the Biblioteca Nazionale Centrale, Rome. It presents evidence for the identification of the anonymous author as Giuseppe Valeriano (L’Aquila 1542-Naples 1596), whose lost treatise on painting was described by his friend Gaspare Celio in the biography dedicated to Valeriano in Celio’s Vite degli artisti (1614). Analyses of the manuscript’s materiality and content here provide evidence of the attribution and date, between 1586 and 1596. The rare manuscript, consisting of four books, is a textbook for artists who needed to learn to paint sacred images properly. The first book defines painting as a medium, its importance, and its usefulness for religious purposes. It also introduces a canon of five excellent painters to look at while training: Polidoro da Caravaggio, Titian, Correggio, Raphael and Michelangelo. The second book is a treatise on anatomy for artists, once replete with over ninety illustrations that have since been lost. The third book deals with composition according to the post-Tridentine norms of painting. The final book is an unfinished treatise on color, describing how Correggio, Titian, and Raphael used pigments to represent different textures of human skin and clothing. In preparation for the critical edition of the entire manuscript, this article demonstrates the importance of Della pittura in advancing our knowledge of artistic training and practice in late 16th-century Rome.