Molochite 200s (Very Fine)
Manufactured using calcined china clay which is a refractory white grog. Fine grades are used to reduce shrinkage of engobes and to increase resistance to thermal shock. Coarser grades are used in clay bodies such as Earthstone.
Grog (ground, fired body) is added to some clays to provide a proportion of fired and often refractory material to the body. This adds texture, along with bite, for better control during forming. The grog also acts as an opener and helps the clay to dry uniformly. As the grog is already fired it also cuts down on the overall shrinkage thus reducing problems of cracking and warping. Most are fired to high temperatures of at least 1300ºC.