CLAY (5) Centering
Centering clay is the first step in pottery to shape a round, uniform object like a bowl, pot, etc. A lump of clay must be placed correctly in the center of the wheel and forced by hand into a symmetrical form. Your hand movements to center the clay are known as coning. As the wheel turns, you apply pressure on the clay with both hands, if it is not correctly centered, your work will not be circular.
The next section; Clay (6) Opening