The COPPR has a lovely subtle copper colour, and is easier to work than the BRONZ as it sticks better to itself.
It also has a simpler firing schedule. Both the COPPR and BRONZ need to be fired in an oxygen free environment. This consists of submerging your piece in carbon in a stainless steel pan and kiln firing.
The COPPRclay can ONLY be fired in the Coconut Shell Activated carbon.