Andrea della Robbia (Italian, 14351525)
Terracotta with tinted tin–enamel glazes; Diam. 64 1/2 in. (163.8 cm)
Purchase, Joseph Pulitzer Bequest, 1921 (21.116)
The Florentine sculptor Luca della Robbia (1399/14001482) used tin glaze in a new and imaginative way, by mixing batches of white glaze with oxides of various metals in a finely powdered form. When fired, the resulting glazes were colored in their entire mass with blues from cobalt, yellows from antimony, greens from copper, purples and violets from manganese, and oranges and browns from iron rust. These colored glazes were applied to the already fired terracotta sculptures in a liquid form with water admixed, and fixed in a second firing. They covered the sculptures with washes of color in areas needed for clothing and background details, much as paints would do for a picture. The colors were permanent and could be exposed to the weather.
Luca's family continued the use of his innovation in their workshop in Florence and elsewhere until late in the sixteenth century. His nephew Andrea, the creator of this large relief, also made freestanding busts and reliefs with religious, heraldic, or moralizing subjects, as here, with the figure of Prudence, one of the Cardinal Christian Virtues. It is likely that this large relief, which has part of the brick wall adhering at the back from its original installation, was once placed in a prime location with reliefs of the three other Cardinal Virtues (Courage, Justice, and Temperance). The encircling wreath of four fruiting plants is very typical of the della Robbia workshop. The segments probably indicate the seasons of the year, with pine cones for winter, grapes for autumn, lemons for spring, and gourds for summer.