Firing Porphyry in the Italian Renaissance Kiln

In the second half of the sixteenth century a Neapolitan architect and painter, Pirro Ligorio (1510–1583), wrote a recipe for painted porphyry. As he explained, ‘when we want to imitate porphyry with paint, we make a plane of purple colour or lionato rossetto, but with some darker parts, and then, using flesh colour, we cast some small dots across the surface with a brush’.1 Here Ligorio was eloquently codifying knowledge which by then was already widespread. The time of experimentation, and of the pursuit of suitable tools and methods for carving porphyry, had already passed. This chapter will focus on an earlier era, that of the mimetic venture of the Della Robbia family of artists, who strove to produce a porphyry-like material in the ceramics kiln. The Della Robbia did not merely paint the surface of their sculptures to imitate the visual properties of the rock, as described by Ligorio, but rather, by means of a laborious and quasi-magical process of firing porphyry in the kiln, they participated in a dialogue between the artificial and the natural, between representation and actual substance.