Maiolica, the refined, white-glazed pottery of the Italian Renaissance, was adapted to all objects that were traditionally ceramic, such as dishes, bowls, serving vessels, and jugs of all shapes and sizes. It was also used as a medium for sculpture and sculptural reliefs, as well as floor and ceiling tiles. The latter were rectangular, laid side by side across specially adapted joists.
Maiolica is distinguished by its white, opaque glaze, due to the presence of tin oxide, a powdery white ash. Tin was an expensive imported substance, which made maiolica a far more expensive commodity than ordinary pottery. Great care was taken to refine and shape the local clays, which varied considerably in color and weight. A maiolica workshop would have consisted of about eight workers, each with a special task—gathering fuel, preparing and firing the kilns, preparing the raw clay, throwing or molding it into shapes, mixing and applying the glaze, and decorating it with ceramic pigments. All worked under the leadership of a master potter, who in most cases would have owned the workshop.
The tin-glazed surface was smooth and shiny but not brilliant. In an evolution similar to that which led from fresco and tempera painting to oil painting, in the sixteenth century maiolica workshop procedures applied a second, clear glaze to maiolica objects, which produced a brilliantly shiny surface and enhanced the color decoration. The tin glaze itself was a mixture of the elements of ordinary lead glaze and tin oxide. This was liquefied with water and (most likely) a little gum arabic, into which the clay objects were dipped. When thoroughly dry, the surface was ready to be painted, a difficult process requiring great control by the painter, as the surface in its pre-fired condition readily absorbed the pigments, themselves dry powdery metal oxides mixed with a little water and perhaps gum arabic.
Around 1430–60, the range of colors available for decorating maiolica expanded from purple-brown derived from manganese and green from copper, to blue from cobalt. By the early sixteenth century, a full range of colors was available: blues, greens, yellows, oranges, white, black, and brown, and several tones of luster colors such as ruby red, pink, yellow, and reddish brown. Judging by surviving examples, the luster colors were the specialty of several workshops in Deruta and of Maestro Giorgio and his descendants in Gubbio.
Florence led the way in the fifteenth century in the production of maiolica. The output of the city’s workshops represented a technical and aesthetic advance on the process as it was learned from Islamic Spain (it is not known who introduced the technique into Italy). Before the turn of the sixteenth century, important centers in Naples, Pesaro, Faenza, Rome, and Deruta were making fine maiolicas. From the sixteenth century, surviving examples of great beauty were made in Forlì, Cafaggiolo, Castel Durante, Rome, Urbino, and Venice, as well as several places in Sicily. For important commissions, sources of design were either new drawings incorporating the arms and insignia of the client for one-of-a-kind pieces, or prints and other available drawings that were often repeated in an early form of mass production for a larger popular market.
Maiolica had a last flowering at Urbino in the last third of the sixteenth century. But by the end of the century, production had declined due to economic constraints, although the so-called bianchi di Faenza, lightly decorated white wares made in Faenza, continued the tradition of new designs and fine workmanship.