After smoothing, you can use a length of wire to slice the base of your piece and free it from the wheel.
As it spins, the sponge is dragged up gently from top to bottom. This happens repeatedly until the desired smoothness is achieved. A more advanced version of this process uses a flat wooden smoother tool to burnish the clay before firing. After smoothing, you can use a length of wire to slice the base of your piece and free it from the wheel.