| Reduction is created by the
extraction of oxygen from the oxides in the glaze. Basically,
the kiln atmosphere is starved for air. In order for the gas
to burn it pulls oxygen out of the clay and glaze creating unique
glaze effects.
In the stony gray butter dish (#11), iron is pulled from the clay body into the glaze to create the brown and black spotting on the surface as well as the all over gray coloring. Reduction fired copper glazes (#14 red/purple/blue) are the hardest glazes to fire. Copper can create some wonderful reds that never look exactly the same from piece to piece. Their surface coloring depends on where they are placed in the kiln, how thick the glaze is applied and how much reduction has occurred. |