The storage jar is remarkably regular and SYMMETRICAL, a form typically accomplished with the aid of a potter's wheel. But it was made well before the introduction of the wheel in Japan. The artist built up the vessel from a base using long coils of clay rolled by hand, pressed together, and formed into a distinctive shape. Imaginative handles and rims were also shaped by hand and applied at the top.
Jomon potters used a coarse-textured clay that was available near their dwelling sites. Sand or crushed stone was added as a TEMPER to give the pots greater structural strength as the pots were being formed.
To make them more durable, unglazed Jomon wares were stacked in simple
open pits and "cooked" by wood fires built around and over them.
The fire was fed continuously for about an hour and then allowed to die
down. The low firing temperatures ranged from 600° to