Ceramics of Indigenous Peoples of The Americas - Materials and Techniques

Materials and Techniques

The clay body is a necessary component of pottery. Clay must be mined and purified in an often laborious process, and certain tribes have ceremonial protocols to gathering clay. Different tribes have different processes for processing clay, which can include drying in the sun, soaking in water for days, and repeatedly running through a screen or sieve. Acoma and other Pueblo pottery traditionally pound dry clay into a powder and then remove impurities by hand, then running the dry powder through a screen, mixing it with a dry temper, and then mixing water to create a plastic paste. In preparing the clay, potters spend hours wedging it to remove air pockets and humidity that could easily cause it to explode during firing. The clay then needs to "cure" over time.

Coiling is the most common means of shaping ceramics in the Americas. In coiling, the clay is rolled into a long, thin strands that are coiled upon each other to build up the shape of the pottery. While the potter builds the coils up, she also blends them together until there was no trace of the ropes of clay entwined to form the pot, no deviation in the thickness of the walls, and therefore no weaknesses. Potter's wheels were not used prior to European contact and are only used today by a limited number of Native American artists. Pinch pots and other small clay objects could be formed directly by hand. Hohokam potters and their descendents in the American Southwest employed the paddle-and-anvil technique, in which the interior clay wall of a pot was supported by an anvil, while the exterior was beaten with a paddle, smoothing the surface. In precontact South America, ceramics were mass-produced using molds.

Slip is a liquid clay suspension of mineral pigments applied to the ceramics before firing. Slips are typically red, buff, white, and black; however, Nazca culture ceramic artists in Peru perfected 13 distinct colors of slips. They also used a hand-rotated turntable that allowed all sides of a ceramic piece to be painted with ease. These were first used in 500 BCE and continue to be used today. Slips can be applied overall in washes, creating large color fields, often with cloth, or they can be painted in fine detail with brushes. Yucca leaves, chewed slightly to loosen fibers, make excellent brushes that are still in use today in the American Southwest. Negative painting is a technique employed by precontact Mississippian potters in the Eastern Woodlands, Mayan potters in Mesoamerica, and others, which involves covering the ceramic piece in beeswax or another resist, incised a design in the resist, then soaking the piece with a slip. In the firing process the resists melts away, leaving the colored design.

While still green, pottery can be incised with designs. Cords, textiles, baskets, and corncobs have been rolled over wet clay, both as a decoration and to improve heat dispersion in cooking pots. Carved wood or ceramic stamping paddles are used throughout the Southeastern Woodlands to create repeating designs. Clay can also be added to the main ceramic structure to build up designs.

Before firing, ceramics can be burnished or polished to a fine sheen with a smooth instrument, usually a stone. Glazes are seldom used by indigenous American ceramic artists. Grease can be rubbed onto the pot as well.

Prior to contact, pottery was usually open-air fired or pit fired; precontact Indigenous peoples of Mexico and Pueblo people did make limited use of kilns. Today many Native American ceramic artists use kilns. In pit-firing, the pot is placed in a shallow pit dug into the earth along with other unfired pottery, covered with wood and brush, or dung, then set on fire whereupon it can harden at temperatures of 1400 degrees or more. Finally, the ceramics surface is often polished with smooth stones.