Before an object is glazed, it is often bisque fired. The
purpose of bisque firing is to render the object more durable,
while leaving it porous enough to absorb glaze. Bisque firing
occurs at a temperature (minimum 500-600°C) below that of glaze
firing, and must begin slowly to prevent the object from
cracking or exploding. After an object has been formed and
glazed, it is fired in a process known as glaze firing. Glaze
firing - which occurs at a higher temperature than bisque firing
- fuses the glaze to together in combination with the surface of
the clay body. The atmosphere within the kiln has a dramatic
effect on the final appearance of the fired object. Glaze firing
can be either oxidizing or reducing, depending on the presence
of absence of oxygen within the kiln. Oxidation firing usually
takes place in an electric kiln, where oxygen is present in the
atmosphere. Oxidation is necessary for the development of
certain colours (such as greens from copper) and is often
associated with clean, carefully cont