The exchange of technical knowledge between artists has played an important role in the history of the arts. The lecture aims to illustrate this practice by considering the dissemination of certain materials and techniques in Florence in the early 16thcentury , based on research carried out in recent years on glazed ceramics from the workshops of the Della Robbia family, as well as on the paintings of Leonardo da Vinci, his pupils and followers. This rich Florentine context underlines the place of technè in the arts of fire and in painting practices: it appears as a primordial element in the course of a work's creation. The word technè is used here in the sense employed by Aristotle(Nicomachean Ethics, VI, 4), as it underlines the fact that "art(technè) consists in producing, executing and combining the means of giving existence to one of the things that can be and not be; and whose principle is in the one who makes, and not in the thing that is made". However, not all great artists were great theorists of matter and technique, seeking to conceive new approaches and sometimes spelling them out in their writings. Leonardo da Vinci and the Della Robbias are exemplary in this respect.
As far as ceramics are concerned, it was possible to demonstrate the specific features of glazing, which is inextricably linked to the choice of the clay on which it is based, both from the point of view of precise temperature control and the selection of particularly pure ingredients for white areas or ingredients rich in cobalt and impurities for blue areas.
