How was this bowl made?
The production of lustreware is incredibly complex, requiring several stages of production, two kiln firings, and the use of expensive, specialized metallic oxide glazes. This materiality made the production of lustreware ceramics time-intensive and extremely expensive.
The first step in creating a lustreware is to shape the ceramic's body - or form - from raw earthenware, and let it dry.
The second step is to coat the ceramic in a special lead glaze made with tin oxide that would make the ceramic's body an opaque white.
After this coating the ceramic is then fired in the kiln for the first time.
Typically, ceramics only go through these first three steps; however, luster manufacture requires several additional stages.
After this initial firing, luster ceramicists would then paint on the luster glaze decoration. The colors and tones of these metallic luster paints are incredibly nuanced, and the inclusion of different chemical compounds results in different colors. It is the presence of these silver and copper oxides, typically mixed with clay and ochre, that create the iridescent sheen on the ceramic. At first, lusterware was predominately polychrome including blues, greens, reds, and yellow ochres; however during the 10th century monochrome lusters became popular. The two predominant luster monochromes are red-brown and yellow-brown, which are produced from copper oxide and silver oxide respectively. This shift towards monochrome has persisted since it was first introduced as it enabled ceramists to create stronger, less visually ambiguous designs. The technique of painting on the luster after the ware's initial firing allowed for greater artistic freedom in terms of brushstroke and use of fine lines, making lusterware ceramics some of the most painterly and complex in design.
The vessel is then fired for a second time in a special, smokey kiln at a lower temperature. This creates a "reducing atmosphere" that will deprive the metallic oxides in the luster paint of oxygen, causing them to break down and deposit metallic compounds on the ceramic's glazed surface in a thin film. The kiln temperature is regulated to remain approximately 600 degrees fahrenheit, which softens the initial layer of glaze enough to receive the deposits.
However, the creation of the luster’s metallic sheen is not completed until the ceramic is cooled and the potter is able to rub the surface with a cloth to bring out the luster's shine. It is this final rubbing that creates an iridescence on the ceramic’s urface and finalizes its luster manufacture.
This multi-step process is not only time and energy intensive, but requires specialized equipment in terms of a kiln and specific oxide-mixed paints. The additional materials and extra fuel required for the second firing results in luster production being both expensive and limited in quantity. However, the production of lusterware was also a testament to a ceramicist's skill, as they needed to control for several variables during the glazing and firing process.
Materiality is the single most important element of this bowl as it not only enhances its aesthetic dynamism, but also speaks to when, who, and how the bowl was used.
