This piece was slipcast using Ashraf Hanna stonware clay and after bisque firing various oxides and carbonates were sprinkled on the surface and then  it was wrapped in a saggar of tin foil and fired in a gas kiln. The top was wheel thrown and then smoke fired and attached to the base.
 
What is Saggar Firing?
 
Saggar firing is a traditional ceramics technique used to create unique surface effects on pottery. 
 
Saggar firing involves placing bisque fired pottery inside a container called a "saggar" before placing it in the kiln.
 
Origins of the Term 'Saggar'
 
The term "saggar" is derived from the word "safeguard," as its primary function is to protect the pottery from direct contact with flames, ash, and other kiln elements that could alter or damage the ware.
 
Preparing the Saggar: The saggar, typically made from high-temperature clay, is often pre-coated with various materials such as alumina, silica, or refractory grog to prevent the pottery from sticking to the saggar itself during the firing process.
 
Loading the Pottery: The pottery pieces are placed inside the saggar along with various combustible or organic matter (sawdust, leaves, straw), metal oxides, salts, and other materials with the purpose of producing interesting surface colours and textures when they combust and vaporize.
 
Sealing the Saggar: The saggar is then sealed with a lid or additional clay to ensure that the internal environment is controlled. This isolation helps create a micro-atmosphere around the pottery during firing.
 
Firing: The saggar is placed in the kiln, usually a gas powered kiln as the process can ruin the elements in an electric kiln.  The temperature and atmosphere within the saggar can be controlled to some extent, allowing for a range of effects. The materials inside the saggar combust, vaporise, and interact with the surface of the pottery, creating unique patterns, colours, and textures. The interaction between the combustibles and the clay surface can result in mottled, smoky, or speckled effects. Organic materials can leave behind interesting patterns and imprints, such as leaf shapes or wood grain textures.
 
Cooling and Unloading: After the kiln has cooled, the saggar is carefully removed and opened. The pottery is taken out and cleaned to reveal the unique surface effects created by the saggar firing process.
 
Unique and Unrepeatable: Each saggar firing is unique due to the unpredictable nature of the process. The exact placement of materials, the temperature variations, and the specific conditions within the saggar all contribute to one-of-a-kind results.
 
Historically, saggar firing was used to protect ceramic ware during firing in wood or coal-fired kilns.