History of Chemistry in Ancient and Medieval India, Incorporating the History of Hindu Chemistry by Acharya Prafulla Chandra Ray c12.57

c12.57

Many other slabs of similar composition have been found. These were probably ground to powder like the modern enamels, and used for glazing purpose with the addition of a little soda to serve as a flux. In the case of steatite bodies, there must have been serious difficulties to make the resulting powder adhere properly to the surface of the body. It has been suggested that to overcome this, the powder might have been mixed with certain oils, which would volatilize at high temperatures leaving no trace behind: or, the slabs might have been heated to a semi-fluid state and then applied to the body of the material to be glazed, followed by a prolonged heating of the object in order to make the glaze flow freely over it. The layer of the glaze has, in fact, been found generally to be smooth and thin No evidence of over-firing has, however, been detected, which would produce a matt or pitted surface.