Non-metal oxides which form acids on contact with water.
The physical properties of the elements that make up a glaze can be quantified, for example, thermal expansion, density, mechanical strength, electrical conductivity and Opacity. These qualities can be predicted (to some extent) by the proportion of the elements in a glaze, using the Additive Law as proposed by Winkelman and Schott.
Aluminium Oxide (Al2O3).
Usually increases the viscosity of a glaze.
Common raw materils are Alimina Hydate, Calcined Alumina and Clays.
An amphoteric oxide.