Saggar firing is enclosing pottery in a protective container, or saggar, with combustible and colouring materials such as sawdust, salt, copper and banana peel, so the fumes mark the surface with smoky, flashed colour during the firing.
What Is Saggar Firing?
Saggars were originally clay boxes that protected fine ware from ash and flames in fuel-burning kilns. Today potters use them to do the opposite: create a little local atmosphere around a piece, full of smoke and fumes, while firing in an ordinary kiln.
A saggar can be a lidded clay box, a stack of kiln bricks or simply a wrap of aluminium foil around the piece. Inside go materials that burn or vaporise, such as sawdust, straw, seaweed, dried fruit peel, salt, copper carbonate or iron sulfate, each leaving its own colours.
Saggar work is usually burnished and bisque fired first, then saggar fired at low temperatures, often around 800 to 1000 °C. The results are unglazed, porous and decorative, not food safe.
Because it produces smoke and fumes, saggar firing in an electric kiln needs strong ventilation, and many studios only allow it in a dedicated kiln or outdoors. Some materials, such as copper and iron sulfates, need careful handling with gloves and a mask.
This pottery glossary entry from Le Studio Art Space is general educational content. Always follow the clay, glaze and kiln makers’ data for your own materials and equipment.