The Clay

• Pourable ceramics clay -- referred to as "slip" -- comes from different mixtures of clay and water. Porcelain is nonporous and strong enough to make oven- and microwave-safe dishes. Stoneware is also nonporous, but less refined than porcelain and has a dense, hard body after firing. Earthenware, such as terracotta, is porous and not as dense as stoneware.
  
  

The Molds

• Ceramic molds are made of plaster that draws moisture from the slip. Depending on the size and complexity of the finished ceramic, plaster molds require one, two, three or more pieces. Ratcheting nylon mold straps in various sizes or using large rubber bands will hold the pieces of the mold together.
  
  

Preparing the Slip

• Casting slip comes premixed but the procedure of "slaking" -- soaking the clay in water -- and making it into slip is straightforward. Carefully measurement proves vital, as too much or too little of any ingredient affects the finished product. The clay requires stirring by hand with a clean stick and using a drill with a paint-mixing attachment.
  
  

Specific Gravity

• The specific gravity of slip, which refers to the proportion of clay to water, serves as a tool to adjust the slip to meet the needs of different projects. The optimal specific gravity varies and is measured with either a meter or mathematically using the weight of the slip.
  
  

Pouring the Slip

• Pouring slip in a mold -- known as "slipcasting" -- is the easiest way to make ceramics. Before pouring, you remove any lumps in the slip with a strainer, lest they stick to the walls of the mold. Pouring slowly prevents splashing and covers all parts of the mold. As the plaster mold absorbs the water, the slip settles, with more added until no perceptible change exists in the level of slip as it dries.
  
  

Drying

• The thickness of the clay and moisture in the mold determine how the piece's drying time. As the clay dries and shrinks away from the plaster, it retains its shape, but remains moist until fired. Storing the drying ceramic in a safe place will keep it from being bumped or knocked over once out of the mold.
  
  

Firing

• Clay must dry completely before placement in the kiln because wet clay will explode as the steam of the evaporating water builds up. Types of kilns include electric and fuel-burning, in various sizes with different maximum temperatures, which determine the type of clay each kiln can fire.