People used materials around them as tools to decorate their pots. Fingernails, sticks, cords and shells were all used to decorate pots. How these tools were used and the designs that were made change from location to location and through time. As coils or slabs were added, early Woodland potters used a paddle wrapped with cord to shape the pot. This technique left a distinctive surface that showed the texture of the cord wrapped paddle. The potters then used their fingernail or sticks to make designs on the wet pots. Late Woodland people pressed cord or fabric into the clay near the rim of the pot. Clam shells were also rocked back and forth along the sides of the pot to create a unique zig zag decoration. Later Oneota peoples used their finger or sticks to decorate their pots.
Step 1 — The first step in the pottery making process was to add temper to the raw clay. Temper is a non-plastic material which is added to the clay before it is worked. Molecules of clay adhere to the temper material and improve the quality of the clay. Temper is added to counteract shrinkage of the clay, it facilitates uniform drying and lessens the risk of the vessel cracking when fired.
Archaeologists are studying prehistoric pots to try to understand how they were constructed. At present no one method of construction has been proven. One technique that has
been suggested is called coiling. In this method, clay is rolled into a thick "rope" shape. These "ropes" or "coils" were placed one on top of
the other and smoothed by hand or tool to make an even surface.
Step 2 — The final shaping of the vessel was done by hand while the clay was still wet. The rim was straightened and sometimes pulled slightly outward. Handles were
attached after the rim had been shaped to the desired angle.
Step 3 — Decoration was applied to the vessel when it was leather-hard. The pot was then allowed to thoroughly dry.
Step 4 — Firing was the final step in the pottery making process. As clay is heated its chemical structure is changed, the actual method used to fire the vessels is unknown, although it is know that kilns were not used. It is likely that the vessels were fired in an open-air situation.
The different colors seen on the pottery vessel are a result of the firing conditions. During the firing process areas that are exposed to oxygen turn reddish in color while areas that are covered and deprived in oxygen turn black or gray. Many pots have gray black spots on their exterior surfaces that suggest contact by a log during firing. Some pots still have black charred cooking remains on their inside or outside. Archaeologists hope that in the future it will be possible to analyze these remains to determine what was in the vessel and how the pot was used.