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-consuming and extremely expensive.
The first step in creating lustreware is to shape the ceramic's 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, which makes the ceramic's body opaque white.
After this coating, the ceramic is 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 paint on the 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. The presence of these silver and copper oxides, typically mixed with clay and ochre, creates 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, 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 more robust, less visually ambiguous designs.
The vessel is then fired for a second time in a unique, 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 luster's metallic sheen is only completed once the ceramic is cooled, and the potter can rub the surface with a cloth to bring out the luster's shine. This final rubbing creates an iridescence on the ceramic's surface and finalizes its luster manufacture.
This multi-step process requires specialized equipment, so potters produce limited quantities of ware. The process is also a testament to a ceramicist's skill, as they must control several variables during the glazing and firing process.
Materiality is the most crucial element of this bowl, enhancing its aesthetic dynamism and revealing when, who, and how the bowl was used.
