Lustreware is a decorative technique where a metallic glaze is used to give an iridescent finish to the pots fired at a low temperature.
“The first use of lustre decoration was as painting on glass. While some scholars see this as a purely Islamic invention originating in Fustat, others place the origins of lustre decoration in Roman and Coptic Egypt during the centuries preceding the rise of Islam. Staining glass vessels with copper and silver pigments was known from around the 3rd century AD, although true lustre technology probably began sometime between the 4th and 8th centuries AD” (wikipedia)
Luster decorated wares are ceramics to which a very thin metallic film has been applied to the glazed surface for decoration. Firing in a muffle kiln fused the metallic glaze to the ceramic body, leaving a hard, lustrous finish. Luster decoration has been used on earthenwares, stonewares and porcelain. (Note: The English use the spelling “lustre”, whereas the American spelling is “luster”.)
Although luster had been used to decorate Spanish ceramics for centuries, its use by the Staffordshire potteries did not begin until the end of the eighteenth century. These wares were also produced in Northern England, Scotland and Wales (Hildyard 2005:177) and were exported in large numbers to North America and Continental Europe (Gibson 1999:15). According to Gibson (1999:174), the “peak of achievement” for lusterwares occurred around 1860, with production waning towards the end of the nineteenth century.
The luster effect was produced as an overglaze finish in a low-temperature reductive atmosphere kiln, using metallic oxides to create different luster colors (Bedford 1965:8). Gold luster was produced using gold oxide and silver luster came from platinum oxide. A copper or bronze finish was created with gold oxide over red-pasted earthenware or copper oxide on white-bodied wares. Pink and purple luster, derived from purple of cassis, a precipitate of gold and tin oxides, were used primarily for painted scenic motifs and ornamental banding (Hughes 1968:81).
The colour of the lustre glaze was also affected by the colour of the body of the vessel. A single layer of copper lustre on bone china or whiteware would be purple, whereas application of a second layer of copper lustre created a copper colour. Thus, on bone china cups and saucers, it was common to have a band of purple lustre with copper coloured painted leaves because the leaves have been painted over the purple band, thus creating two layers of the lustre. Copper and silver coloured lustre were commonly used on red earthenware, but purple was not.” (diagnostic artefacts)