These 2 inch high cones are for use inside the kiln firing chamber. Usually three
cones are used, one for the intended firing temperature, one lower and one
higher. Example: for a Cone 06 firing use Cone 07 as the guide cone (lower),
Cone 06 as the firing cone and Cone 05 (higher) as the guard cone. Cones
should be set in a cone plaque or holder, then placed inside the kiln in a location
where they can be viewed through the peephole of the kiln. When the guide cone
starts to bend it serves as a warning that the firing process is approaching
completion. When the tip of the firing cone touches the plaque, the kiln is to be
turned off. If the guard cone bends the ware has been overfired.
