A saggar is a type of kiln furniture.It is a ceramic boxlike container used in the firing of pottery to enclose or protect ware being fired inside a kiln. Traditionally, saggars were made primarily from fireclay. Saggars have been used to protect, or safeguard, ware from open flame, smoke, gases and kiln debris. Saggars are still used in the production of ceramics to shield ware from the direct contact of flames and from damage by kiln debris.
From the twentieth century studio potters have used saggars to create decorative ceramic pieces. In this use saggars are used to create a localised reducing atmosphere or concentrate the effects of salts, metal oxides and other materials on the surface of their ware.
I prepare my pots carefully for saggar firing. On porcelain clay, I create a smooth surface covered with terra sigillata, which responds particularly well to the saggar technique. Prepared pots are nestled into saggars filled with beds of combustible materials, such as sawdust, less combustible organic materials, salts and metals and plants that I have collected around Dartmoor. . These materials ignite or fume during firing, leaving the pot buried in layers of fine ash leaving mark on the pot surface.