Craftsmanship is all-important in any part of the ceramic process. The materials can be dirty and messy it is wise to wear an apron in the workshop and unless a strict control is maintained over them, the results may be discouraging. Rules often limit the imagination and creativity of the artist, but here are some suggestions which will help insure good results:

1. Avoid sharp, angular edges or corners. They create strain and cracking. Clay adapts itself more readily to rounded edges and soft curves. Also, after firing, an edge that is too sharp can be dangerous like a chipped glass, it is hard enough to lacerate the skin.

2. To add soft to harder clay in a project which cannot be completed in one sitting, slowly soften the hard clay with a damp cloth or sponge. Too rapid absorption of coat of slip before adding new, soft clay.

3. To mend cracks on still-moist clay bodies, probe to the bottom of the crack and fill it with clay of the same consistency. Repeat if the crack reappears. Before allowing it to dry, a piece should be carefully inspected and all cracks repaired. If the clay is hard, the problem is much more difficult; more time and patience are required. First, moisten the area very slowly, probe to the bottom of the crack, and carefully fill it with a solution of slip or clay mixed with 50% by volume of grog.

4. Lightly sponge the surface of a piece, after it is shaped to completion, to remove rough and sharp edges. Do not, however, expect sponging to cover up poor work.

5. If a project is to be worked on over a long period of time, it must be kept damp between operations. A damp closet may be used. This is a specially constructed cupboard which is lined with zinc. An old ice box, a tin box or a butter tub with plaster cast across the top may also serve as storage vessels. The piece should be wrapped in a damp cloth, dampness depending on shape, size, sturdiness and condition of clay. Wrap the cloth around the object, to reduce weight on the clay, and close to the piece, to reduce evaporation.

6. Before a piece of sculpture is permitted to dry, it may need to be hollowed. If it is more than IV2 inches thick at any point, clay should be removed from the center. A half-inch wall of clay should be maintained. Hollowing allows the clay to dry with greater speed and with less stress and strain, and may open up air pockets which would cause disaster during the firing process.

7. How long a piece requires to dry depends entirely on its shape, thickness, and fragility. Slow drying under any circumstances is essential. Rapid drying causes a dry crust to develop on the surface, through which moisture cannot escape, and warping develops. Cracks may also appear at the points of greatest strain. A piece should be allowed to dry in its damp box until the shiny moisture disappears. Then it may be removed and left at room temperature for a day or so, after which it can be placed over a radiator or in a hot box where some means of heating is employed. Pieces must be completely dry before firing. Moisture turns to steam in the kiln and exerts tremendous pressure in escaping. This almost always results in the piece exploding.

To test dryness: In cold weather, place the bottom against the window pane for a few seconds. Look for condensation which will appear on the window if the piece is still too moist. There is no reliable dryness test for hot weather.

Finally, the novice ceramist should be familiar with a modeling material called plasteline, or plastecine. In essence, plasteline is comprised of ball clay, lanolin and glycerine. Since the clay flour is mixed with an oil base rather than water, plasteline is very plastic and will not dry, shrink or harden. It finds its greatest use for sculpting prototypes of cast ware. Unless the artist wishes to make reproductions of his sculpture, he should model directly in clay. Plasteline cannot be fired. A mold must be made of the plasteline figure and slip poured into it. When the mold is completed, the plasteline can be mashed up and used again.