While you are working clay it will be drying out. As clay dries it gets harder. This can be used to your advantage if you are familiar with the different states of clay. You can manipulate and manage the drying or remoistening of clay for particular effects. When you get to the point of understanding and working the variety of possibilities you will be starting to work with the rich and varied language of clay.

Plastic clay is very flexible. In a plastic state it moves very well by pinching, gentle stretching, compressing and impressing. Wads or coils of clay can be pressed together without scoring the surface if a small amount of slip (liquid clay) is applied. Blending surface textures is easy because of the clay's softness, but forms can collapse if overworked or unsupported. If you want to achieve complicated shapes that are organic or animal like, it is best to rough in the general shape from a solid mass of clay and then hollow out the form when the clay has dried to the next stage (several hours or overnight).

Cheese Hard refers to clay, in a Swiss cheese-like density. Impressing or cutting work well to refine the surface. Carving chips stick slightly but it is easy to cut clean lines without bending the form. It is possible to gently coerce a light bend into the clay but radical curves will break. Shapes can be carefully joined at this time. Both joints should be scored and slipped and pressed together as hard as delicacy will allow. The slip that is squeezed out should either be sponged lightly for removal, or, depending on the engineering of the piece, a thin coil of clay should be pressed into the joint for extra support. The piece should be allowed to dry for about fifteen minutes before it is handled. This time allows the wet junction to develop some strength.

When clay is Leather Hard it is in a dense hardened state but it also still has some moisture in it. Pieces can be handled without being deformed and the shape is very strong. Detail carving to refine hard edge geometry, and drawing with a pencil point work well. Carving chips fall away easily. This is the last possible time to join parts together if you've been letting them harden to preserve surface detail. DO NOT wait this long if you are a newcomer to joining shapes as it is most difficult. The fit must be perfect in joining parts because the clay cannot bend to fill gaps. All joints should be scored and slipped. Wait a few minutes before pressing together to allow the moisture in the slip to soften the edges to be connected for a better junction.

Drying should be slow. Fast drying can cause cracking. Avoid drafts. Cover handles and extensions with plastic. When you have an area in a work where plastic clay is right next to cheese hard clay you have a weak area of construction. These weak areas need to dry slowly and under cover rather than being exposed to rapid heat or drying quickly.

Bone Dry clay is very brittle. It appears lighter in color than wet clay because most of the moisture has evaporated. In this state a piece is most delicate. It has no moisture and it is unfired. Transportation must be done in a well padded box so the piece is fully supported. The clay has no flexibility and needs to be handled with utmost care. It is not possible to repair cracks or breaks at this point, and the clay cannot be re-wet to bring it back to leather hard. Fine sandpaper or a planing tool can be used to flatten out bottoms or to smooth surface irregularities, but dust is a hazard to be managed carefully.

All of the above states of clay are called Greenware.

All work must be bisque fired before it is ready for Glazing. Once glaze has been applied to bisqueware it goes through a second firing known as a Glaze Fire. This firing takes place at a lower temperature.

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