Pottery-making Techniques

Understanding the pottery-making process is invaluable in identifying and appreciating ancient Southwestern pottery. 


Clay Composition

The first step in making pottery was to collect and prepare appropriate clay. Clay was usually obtained locally, as it had to be carried from the source to the village. Because of this, clay is an important factor today in identifying pottery. In the most general terms, Mogollon pottery is made from brown clays, Hohokam from buff, Anasazi from white to gray, and Salado from red. Of course not all clay in one area is the same, and there is a fair amount of variation throughout all types.

RAW CLAY

We are fortunate that when our team of excavators visited the Southwest in 1931, they collected a sample of raw clay from the Canyon de Chelly. These slabs are now quite friable, and the layering of their sediments is easily seen. This raw material would be dried, ground and sifted to remove the impurities. Only the finest clay would be used for vessels.


Temper

Untempered clay will shrink and crack during drying or firing. To alleviate this, various forms of temper were added to the clay to provide greater strength.  Crushed rock, which appears more angular, might also be used. Frequently, old broken pottery was crushed and used as temper.

SAND TEMPER

Sand was probably the most common form of temper, and is seen as tiny cubic granules on close inspection. Water-washed sand is also cubic, but the edges are rounded almost to the point of making the grains appear spherical.

MICACEOUS TEMPER

In Hohokam country, the sand contains  mica flakes, which lends a glittery aspect to the surface of the vessels.

CRUSHED ROCK TEMPER

Crushed rock was used throughout the Southwest as a temper. It is usually barely visible to the naked eye, primarily because it is either volcanic, and therefore much darker than the paste, or tuff, and therefore much lighter.

CRUSHED SHERD TEMPER

In an environment where pottery is made, it would be expected that old broken vessels would be crushed and reused as temper. Angular grains are visible with a hand lens, and occasionally retain their original slip collor along the edge.


Vessel Construction

Once the clay has been mixed with temper and water, it was kneaded into a workable mass and prepared for production. Three fairly distinct methods were used for building vessels.

COILING-AND-SCRAPING

Coiling-and-scraping involved the creation of long, narrow coils which were spiraled upward and outward to form the basic shape of the vessel. This rough form was then scraped and smoothed to give an even finish and to help weld the coils together. This technique was the primary method of vessel construction for the Anasazi and Mogollon.

PADDLE-AND-ANVIL

The Hohokam used a different method, called paddle-and-anvil. A large piece of clay was shaped into a very rough form, then the potter worked the surface thinner and smoother by pressing on the exterior with a paddle while supporting the interior with the anvil.

PINCH POTS

A third method involved simply pinching a small mass of clay into shape. This method of creating miniature pots was found throughout all cultures of the Southwest.