Lustreware or lusterware (the respective spellings for British English and American English) is a type of pottery or porcelain with a metallic glaze that gives the effect of iridescence. It is produced by metallic oxides in an overglaze finish, which is given a second firing at a lower temperature in a "muffle kiln", or a reduction kiln, excluding oxygen.
The technique of lustreware on pottery was first developed in Mesopotamia (modern Iraq) in the early 9th century. Initially mostly decorated with geometric patterns, by the 10th century an Iraqi style with the design dominated by one or two large figures developed. After the Fatimid conquest of Egypt in 969, it became a great centre of lustreware production until the Fatimid Caliphate fell in 1171, soon after the potter's quarter of the capital Fustat (Cairo) was burned in 1169. It is thought that the Fustat potters dispersed to both Syria and Persia, and lustreware appears there about this time; later the devastating conquests of the Mongols and Timur disrupted these industries. The technique had spread to al-Andalus (the Islamic Iberian Peninsula). Hispano-Moresque ware in lustre was mostly produced in Christian Spain, especially in the region of Valencia – in particular Manises – and later Barcelona.Caiger-Smith, Chapters 1–7
Lustre appears in Italian maiolica around 1500, and became a speciality of two relatively minor pottery towns, Gubbio, noted for a rich ruby-red, and Deruta.Caiger-Smith, Chapter 8 Around 1550 an even smaller town, Gualdo Tadino, also began to make some, for about a century,Caiger-Smith, 153–154 which was the last Renaissance lustre, Gubbio having stopped about 1570, and Deruta around 1630. There was a revival in England and other European countries in the late 18th century, when the techniques had largely to be reinvented, continuing into the 19th and beyond.Caiger-Smith, Chapter 9 Meanwhile, Persian lustre, after very little production since the 14th century, revived under the Safavids between about 1650 and 1750, for elegant vessels, especially vases and bottles, densely painted with plant-based designs.Caiger-Smith, 80–83
The lustreware effect is a final coating applied over the ceramic glaze, and fixed by a light second firing, applying small amounts of metallic compounds (generally of silver or copper) mixed with something to make it paintable (clay or ochre). This is then fired in a reducing atmosphere at a temperature high enough to "soften" the glaze from the first firing, and break down the metallic compounds, leaving a very thin ("perhaps 10 or 20 atoms thick") layer that is fused with the main glaze, but is mainly metal. Lustreware normally only uses one colour per piece, and the range is limited – a "gold" derived from silver compounds was historically the most common.Caiger-Smith, 221–236, 225 quoted
Process In the classical process to make lustreware, a preparation of metal salts of copper or silver, mixed with vinegar, ochre, and clay is applied on the surface of a piece that has already been fired and glazed. The pot is then fired again in a kiln with a reducing atmosphere, at about 600 °C. The salts are reduced to metals and coalesce into nanoparticles. Those particles give the second glaze a metallic appearance.
The process has always been expensive and rather unpredictable, always requiring two firings, and often the use of expensive materials such as silver and platinum. The very thin layer of lustre is often delicate, and many types of lustreware are easily damaged by scratching removing the metallic layer, or by contact with acids,Caiger-Smith, 233 probably over time even the mild acids in food.Caiger-Smith, 83, 233 Lustreware has therefore always been for display and occasional rather than heavy regular use, although by the 19th century it could be relatively cheap. Many pieces show the lustre effect only working correctly on parts of the surface, or not at all. Apparently these were still regarded as fit for sale.
Islamic lustreware Precedents in glass Lustre decoration was first used as a glass-painting technique.Caiger-Smith, 24–25 Lamm (1941) and Clairmont (1977) placed the origin of motifs appearing on lusterware decoration in Coptic Egypt, however, this hypothesis is disputed. Staining glass vessels with copper and silver pigments was known from around the 3rd century AD,Carboni, S. 2001. Glass from Islamic Lands. London: Thames & Hudson, Ltd., p. 51. although lustreware technology probably began sometime between the 8th and 9th centuries AD.Caiger-Smith, 24; Pradell, T., Molera, J., Smith, A.D., Tite, M.S. 2008. The Invention of Lustre: Iraq 9th and 10th centuries AD. Journal of Archaeological Science 35, 1201–1215, p. 1201. The earliest recipe for luster production appeared in 8th century AD "Kitab al-Durra al-Maknuzna" by Jabir ibn Hayyan. Much of the knowledge of the behaviours of metallic compounds in turn came from metalworking, where cheaper substitutes for gold in gilding had been developed much earlier.Caiger-Smith, 25
A fragment of lustre glass from Fustat is dated to the 779–780, and a bowl (Corning Museum of Glass) was made in Damascus between 718 and 814; otherwise we know little of the history of the technique on glass. Lustre was used in Islamic glass only briefly, and never spread to other areas as lustre on pottery did.Battie and Coleman, 43 A similar technique was used to make iridescent Art Nouveau glass, with more of a "rainbow" effect than a single shiny colour, from the late 19th century.Battie and Coleman, 147–149
Mesopotamia
The first lustreware pottery was probably made under the Abbasid Caliphate in modern Iraq in the early 9th century, around Baghdad, Basra and Kufa. Most pieces were small bowls, up to about 16 cm wide, but fragments of larger vessels have been found, especially at the ruins of the Caliph's palace at Samarra, and in Fustat (modern Cairo). Fragments have been found as far away as Spain, North Africa, and Pakistan. Unlike the great majority of later lustreware, these very early pieces used three or four different lustre colours, from silver and copper compounds.Caiger-Smith, 21
The earliest forms of lustreware were decorated with three to four colours, but as time went on the colours used was reduced to two. Recent studies have argued that the preference between polychrome and monochrome has to do with the price and availability of materials. This leads to more monochrome wares being produced over polychrome.
Early Islamic lustreware ceramics were predominately produced in Lower Mesopotamia during the ninth and tenth centuries. In the Great Mosque of Kairouan, Tunisia, the upper part of the mihrab is adorned with polychrome and monochrome lustreware tiles; dating from 862 to 863, these tiles were most probably imported from Mesopotamia. The reminiscence of shining metal, especially gold, made lustreware especially attractive. The bowls were painted with ornamental patterns and designs. Some pieces were signed by their makers, this acted as an indication of the admiration towards each craftsman. Trading in the Middle East was very popular.
Abbasid lustreware was traded within the Islamic world. The city of Baghdad, Iran and surrounding cities were part of the Silk Road economic system of trading during this period. There was a movement of goods generated between Iraq and China which triggered artistic emulations both ends, as well as some transfers of technologies, notably in the realm of ceramics.
Some Abbasid lustreware can be differentiated by figural vs. vegetal design where some include icons and others show plant life. Some displayed both plants and figures. At this point in time, there was an aesthetic preference for completely covering the surface of objects with ornamental decoration, and this is also the case for lustreware ceramics. As lustreware made appearances in other cultures and countries, less decoration was introduced. Abbasid lustreware can either be polychrome, monochrome or bi-chrome when it comes to the colours featured in the ceramics. The polychrome and bi-chrome types are generally associated with the ninth century, while the monochrome type is associated with the late ninth or tenth century. The different colour types share the quality of the surfaces changing under different conditions. Abbasid potters would normally decorate polychrome bowls with vegetal and geometric patterns, while the monochrome bowls usually had large, centrally placed figures. They are visually sensitive and their appearance can change dramatically in particular conditions.
Fatimid Egypt The Fatimid court in Egypt was large, rich, and extravagant, producing one of the great periods for lustreware, which was the only luxury type of pottery at the time. The clay-bodied earthenware used was "made from coarse clays" and mostly "fairly roughly made",Caiger-Smith, 39 but the best painting was very fine, and in the mature Fatimid style, characterised by "extraordinary liveliness".Caiger-Smith, 38 The painters may well have bought in standard glazed vessels made by others. The decoration was very varied, partly reflecting the mix of influences from the earlier Mesopotamian tradition, and the Fatimids' own origins to the West, in North Africa and Sicily, as well as the existence of a number of different workshops.Caiger-Smith, 38–39
Only two pieces are datable, by inscriptions naming the patrons, both to early in the period, to the reign of Caliph al-Hakkim, 996–1021, for whom one piece was made. At this period the style was still developing from earlier pieces, but a new style with brighter, warmer, colours was probably established by the mid-century. Gold, red and orange colours evoked the sun and were regarded as auspicious, as were some of the animals who were painted.Caiger-Smith, 39–41
Persia
Lustreware began to be made in Persia when it was part of the Seljuk Empire, whose ruling dynasty and top elite were ethnically Turkish. But Persia was ruled by the Khwarazmian dynasty, initially as vassals of the Seljuk, until in 1190 they severed these ties and ruled independently until the devastating Mongol conquest beginning in 1219. The fifty years from 1150 saw great developments in Iranian ceramics. Firstly the fritware body and the glazes used on it were greatly improved, which allowed thinner walls and some of the translucency of Chinese porcelain, which was already imported into Persia, and represented the main competition for local fine wares. This "white ware" body was used for a variety of styles of decoration, all showing great advances in sophistication. Apart from lustreware, the most luxurious type was mina'i ware, which used polychrome overglaze enamelling, the first pottery to do so. This also required a light second firing; some pieces combined the two techniques. The earliest dated Persian piece with lustre is from 1179. Although an influx of craftsmen from Fustat is usually predicated, these may have been painters rather than potters, as local vessel shapes and the Seljuk "white ware" body are always used. The main colour of lustre paint used was gold; this needs to be distinguished from the overglaze application of gold leaf found in many later mina'i pieces.Osborne, 144–145; Caiger-Smith, 57–65; Watson (1985), 325–326
Lustreware was certainly made in Kashan, and this may well be the only place of production (as it probably was for mina'i ware).Caiger-Smith, 57–59 Though the Mongol invasion, reaching Kashan in 1224, seems to have greatly reduced production until the 1240s, to judge by dated pieces, it continued, initially with little change in style.Caiger-Smith, 75 This was not the case for mina'i ware, which virtually disappears after 1219.