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 were expected to last for about 40 firings; each potbank made their own in a saggar making workshop. Saggars were made from fireclay, by a "saggar maker" and two assistants: the "framemaker" and the "bottom knocker". The framemaker beat the clay into a sheet on a metal table using a large mallet, the "mow" or "mawl". Using a "frame" he would cut it to size, sprinkle it with "sawdust" and wrap it round a wooden block to make the walls. The framemaker was usually an apprentice in his late teens. The bottom knocker, usually a boy in his early teens,