A large scale photographic registering and study of punched decoration in 14th century painting have been carried out by the author and M.S. Frinta. As a general rule it seems that every workshop in this period had its own set of tools, used by all members of the shop but not normally by outsiders. Certain exceptions to this rule have been found and one is discussed - the identity of the Ovile Master. Appendices reproduce 223 punch marks, chronological tables of punch mark occurrences with reference to works by Simone Martini and Lippo Memmi, and by the Ovile master, details of punches used by 13 Sienese painters and their shop relationships, 2 tables illustrating the situation in Florence and punching tool diffusion and workshops interrelationships in Tuscany c. 1320-1420. Bibliography (35 entries) 25 photographs (details of punch marks).