What is Ceramic Slab Building? How about Soda Firing? Learn more about Clay, Slips, Stains and More!

Slab building is the process of flattening chunks of clay into flat manageable pieces with a rolling pin or slab roller. The flat sheets of clay can be altered in any way to achieve an artistic goal. This ceramic character was built from a flat slab, stood upright and formed into a hollow cylinder.

Soda Firing is an atmospheric ceramic firing technique that introduces baking soda and soda ash into a high fire kiln at peak temperatures. When the soda enters the kiln it vaporizes and creates random lustrous coatings on all the work. There's no way to control how much soda gets on each piece, so the outcome of a soda firing is always unique. Some pieces may get heavy coats of the vaporized soda, while others only get light dusting. The soda leaves tones of bright white to dark complex oranges. Whatever the outcome may be, Soda firing is a great technique to get brilliant rich tones on your ceramic projects.

Terra Sigillata, similar to engobes or clay slips, is a watery, pasty colored clay that is often used to decorate the surface of ceramic pieces. It is applied when the work is still at its green stage, meaning, it hasn't undergone any firing. Applying slips too thick or when your project is too dry can lead to cracking or peeling.

Using ceramic stains is another way to decorate your ceramic pieces. Unlike clay slips, stains are applied after the piece has been bisque fired. Stains come in many different colors and formulas and can be applied with an artists brush for fine detail. They are often applied liberally then wiped off leaving only the cracks and grooves stained, emphasizing the details of the work.

The pictures are of a soda fired ceramic figure I made in 2005. I used the slab building method to gain the tall stature of the project. A black stain was applied to emphasize the deep grooves; A black slip was used to decorate the surface. This is one of my favorite pieces to date, all the orange tones are products of the soda firing. No glazes were used.