Clay can be shaped when it is wet by squeezing it between the fingers, “throwing” it on a potter’s wheel, or pushing it into a mould. Before using any of these methods, the potter must make sure that there are no air bubbles in the clay. If there are, the air will expand when the clay is baked, and the article may explode, breaking other items in the kiln as well. However ceramic articles are produced, they are made a little larger than the finished product needs to be, as they shrink slightly when baked.
1. Start off with clay of the proper consistency: soft enough to throw easily, yet not so soft that it will quickly collapse. Clay that’s too hard or dry is very difficult to throw. Be sure to wedge the clay carefully up to 100 times, taking care not to fold it in a way that might trap air bubbles within. Mold into as perfect a cone shape as possible, and smooth out all cracks.
2. Slam cone onto the center of the wheel head or bat. Slowly spin the wheel to see if clay is off center; if so, gently slide cone toward the center as much as possible while the wheel is turned off.
3. Thoroughly wet the clay and start wheel turning to begin centering process. Cup hands evenly around clay and force cone upward and downward a few times to align the clay particles. Then firmly press inward with one hand, and downward with the other, making sure the entire exterior surface of the clay hump is in contact with a portion of the hands. Keep hands firmly positioned in one spot, and with wheel spinning rapidly, steadily maintain that position until the clay offers no resistance, periodically wetting it as necessary. Whenever you remove your hands from the clay, be sure to do so SLOWLY, so as not to knock the piece off center.
4. Once the clay is centered, cup hands around it and allow thumbs to glide into center while wheel is turning. Press slightly to make dimple, or impression, in the middle. With both thumbs and one of forefingers, steadily press downward in center to make a hole in the clay that’s roughly 1/2 to 1/4 in. from the bottom. Periodically stop the wheel and check the depth by poking through the floor of the pot with a needle tool until the desired thickness is reached.
5. Now use forefingers or thumbs (whatever’s more comfortable) to open floor of pot outward, being sure to slide fingers across the clay STEADILY, at the same level as the desired thickness of the floor of the pot. Continue to open the clay outward until the inside diameter of the pot is roughly 10% wider than the desired inside diameter of the finished piece, to plan for shrinkage.
6. Begin to pull clay upward with fingers or knuckles of both hands, one on the outside, the other inside. First undercut the bottom edge of the pot with outside fingertip to form a clay ledge. (Always make sure to re-set the rim of the pot after each movement, to keep it on center.) With fingers of inside hand slightly higher than those on the outside and outside fingers (or knuckle) positioned underneath the clay ledge, gently squeeze the clay between the fingers at an even pressure, and steadily pull upward at the same rate the wheel is revolving. (At this stage, the wheel should revolve at a medium to slow speed.)
7. Repeat the process until the clay walls have reached an even thickness and desired height. If you accidentally knock the clay off center or end up with walls that are uneven, try this: apply a straight-edge wooden rib to the outside of the pot, and hold your left forefinger at a 90 degree angle, pointed downward, on the inside of the pot. Slowly spin the wheel and force the wall of clay between the inside forefinger and outside straight edge back into a uniform thickness, slowly and steadily gliding upward until entire wall is uniform.
8. Gently shape the pot with fingers or ribs, re-set the rim, and release from the bat with a wire or string cutter.
Picture Credit : Google