While visiting Florence, Niceron was shown a unique perspective drawing tool devised by the painter Cigoli, one of Galileo’s friends. He viewed examples of anamorphic drawing techniques and Alberti’s perspective boxes. All of these make an appearance in this treatise. Galileo’s student, Vincenzo Viviani wrote: “The famous Cigoli, regarded by Galileo as the foremost painter of his time, attributed in great part whatever he had of good to the excellent writings of the aforesaid Galileo, and particularly prided himself on being able to say that in perspective Galileo alone had been his master.”