Derived from the Greek keramos meaning “clay”, the generic term “ceramics” refers to all clay-based objects that have undergone an irreversible physical-chemical transformation during firing. Dating back to the Neolithic Period, ceramics constitutes the earliest “fire art” invented by man, predating both glass- and metalworking. Ceramics is not only an important cultural marker in most societies, it also represents the most abundant manmade material.
Whether utilitarian or artistic in nature, ceramic objects reflect changing lifestyles and testify to a society’s technical advances (notably its mastery of the four natural elements: earth, water, air and fire). Ceramic creations reveal a people’s customs, its eating habits and cultural practices during a given period.
From everyday objects to research subjects to exceptional works of art, ceramics remain an inexhaustible source of inspiration.
Terracotta objects made from common clay, varying in colour from grey to red depending on the clay’s composition. Red clays are ferruginous, while white clays contain varying amounts of chalk, silica and/or kaolin. Pottery can be made by shaping, turning or moulding, or by the layering of clay coils. Firing is carried out between 800° and 900° C. Pottery is glazed when the porous paste has been rendered impermeable with the application of a glaze or enamel.
Ceramics made from a tender, clayey, porous paste covered by an opaque, impermeable glaze. Several types of faience exist: lead-based faience, stanniferous faience (containing tin oxide) and faience fine made from top quality clay chosen for its whiteness. Faience can be adorned with both “high-fire” and “low-fire” glazes and designs. For the former, the faience is subjected to a single firing, with the design – painted onto unfired enamel – supporting the high-temperature firing required for the paste and enamel (around 900° C). For the latter, the design is applied to a pre-fired object following the enamel’s application; the colours mixed with fondants can support only a low-temperature firing (650° to 700° C).
Porcelain is a type of ceramic whose paste has been thoroughly vitrified (rendering it impermeable) and that stands out for its whiteness (similar to faience fine, which can be difficult to distinguish from porcelain). Porcelain is generally characterized by its exceptional translucency. This type of ceramic was invented in China in the 7th or 8th century. Following its first importation to Europe during the Middle Ages, Europeans began producing imitations, manufacturing various types of white translucent ceramic.
Hard-paste porcelain (impervious to steel) and soft-paste porcelain (lacking kaolin and can be marked by steel) constitute the two main families of European porcelain, which are generally covered with a transparent glaze or enamel allowing for the whiteness of the paste to show through.
Today, the Manufacture workshops produce four separate porcelain pastes: hard paste (dating from the 18th century and containing 75% kaolin), soft paste (this variant of the 18th-century paste, containing very little kaolin and 50% bone ash, is the only phosphatic soft-paste in France), new paste (invented around 1882, containing 45% kaolin), and white paste or Antoine d’Albis paste, similar to hard paste (named after the Manufacture department head who perfected it around 1965).
Made with paste containing a high percentage of silica and supporting high-temperature firings (1200° to 1400° C), stoneware is partially vitrified during firing.
While pottery and faience are made using porous pastes that must be rendered impermeable with the application of a glaze or enamel, stoneware is similar to porcelain in that its paste is thoroughly vitrified and therefore impermeable even unglazed.
Therefore, ever since stoneware’s invention around the 4th century in China, its subsequent introduction to the Middle East and its development in Europe starting in the Middle Ages, potters have only applied glazes to stoneware for aesthetic purposes, while exploring and combining various materials and forms.