Italian Ceramics: Catalogue of the J. Paul Getty Museum Collection

were imported from Cornwall via Flanders, making

them expensive^6 —for the front of a dish or the exterior

of a pot, where the glaze's brilliance and stability for

painted decoration were most important, relegating the

less pricey lead glaze to the reverse side or interior.

Late medieval maiolica displays a limited range of

colors composed primarily of green from acetate or car­

bonate produced by the action of vinegar on copper,

white from tin (though not used overall at this early

date), and purplish brown from manganese. Although

rare, light blue and yellow also appear at this time.^7

By the early fourteenth century, especially in Emilia-

Romagna and Tuscany, one finds the first known dark

blue-glazed works of the Christian West. By the mid-

Quattrocento, Italian vasai, or potters, had developed a

rich palette that included a deep blue from cobalt oxide

mixed with quartz or sand, a more purple-colored man­

ganese brown, and brilliant yellows and oranges from

mixing antimony and ferric oxide. Although red occa­

sionally appeared, no true red from vermilion was used

before 1700, since this pigment proved too volatile to

survive contemporary firing techniques.

The application of silver and copper oxides before an

additional firing produced the gold, red, or pearly metal­

lic reflections characteristic of lusterware. These oxides

were sprinkled or painted in a thin wash onto the sur­

faces of the ceramics. Introducing smoke into the kiln

during firing by narrowing the air inlets to the fire cham­

ber and adding wet or resinous fuel (such as rosemary or

juniper branches [fig. 5]) removed the oxygen from the

pigments, leaving the painted areas with a thin metal

coat. When rubbed, these metal deposits produced the

shimmering, iridescent surface characteristic of luster.

Sometimes a final coperta (cover) glaze was applied to es­

pecially precious objects, which functioned like a clear

varnish, fusing the pigments and leaving a particularly

shiny, jewellike surface. (A coperta is composed of

marzacotto [cooking mixture] made by fusing sand with

calcined wine lees.)

Maiolica painters needed a sure hand: once applied,

pigments were partly absorbed into the raw tin glaze

and could not be imperceptibly altered or erased.

These artists also needed a thorough knowledge of their

(^5) Cipriano Piccolpasso (Italian, 1523-1579). Folio 49V from Li tie libri
dell'arte del vasaio (1557). London, Victoria and Albert Museum.
Resinous fuel is added below the kiln while plates placed above the kiln
serve as test pieces that the workmen periodically check to determine
when the right temperature has been reached to develop the luster.
4 Introduction