In order to create a bowl on a potter's wheel, the craftsman has to center the lump of clay on the girelle (top plate) of the wheel and then create a cylinder by turning. He must then pierce the center of the ball of clay with his thumb and then gradually widen the hole with both thumbs. The bowl is turned and built first from the inside, and the exterior finishes are then made by turning. For a smooth rendering, the potter regularly passes a wet sponge over the still damp surface of the clay to eradicate all the impurities and traces.