Raku Glass A Kiln Firing Process, continues, from Kiln Fired Glass - Copper & Metal Inclusions, the use of copper inclusions with the introduction of Boyce s new Reactive Dry Enamels. Copper and aluminum when reduced with reactive enamels create unexpected and stunning colors. As in Raku, the fire in the kiln alters the copper and produces fuming metals with iridescent qualities, a natural consequence of a reducing atmosphere at high temperatures. These books will inspire and motivate the glass artist to new heights in the creative world of fused glass.