Saggar kiln debris. Modern saggars are made of alumina ceramic, cordierite ceramic, mullite ceramic silicon carbide and in special cases from zirconia. By far the largest number of UK pottery manufacturers were based in and around Stoke-on-Trent in a region known as The Potteries. Their businesses, locally known as potbanks, fired their wares in distinctive bottle ovens. At the turn of the twentieth century over 4,000 of these were in use, although by 2014 only 47 survive, all of which are no longer in production but are listed buildings. The saggars were used for the biscuit and the glost firing. They
Saggar glazed and again placed in saggars prior to being glost fired. Ware may then be decorated, and placed on refractory "bats" and fired again such as in a muffle kiln. A "Saggar Maker's Bottom Knocker" was a name considered sufficiently amusing for it to be featured on the television panel show What's My Line?. Whilst saggar making was a skilled craft, bottom knocking was far less skilled, consisting of beating clay into a metal ring. 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