Several years ago, conservators at the Opificio delle Pietre Dure in Florence embarked on the restoration of Lorenzo Ghiberti’s Gates of Paradise (1425–52) (Fig. 194).1 After removing stains of age – abject layers of dirt – from the doors, the conservators found, to their surprise, that several exquisite impressions of various stamps had been punched into the bronze surface of the back of the right door (Figs. 195–197). Among the small marks are iterations of Florence’s primary patron saint, John the Baptist, as well as dolphins, rosettes, and imagery related to the Florentine fleur-de-lis, an emblem of the city. The marks, which are distributed around the armature of the door, were struck into the back of the door after it was cast, probably while it lay in a horizontal position in Ghiberti’s foundry across the street from the hospital of Santa Maria Nuova.2