The fuming process, termed kosai ware was discovered by Biz Littel. The pieces are glazed with different metallic glazes and placed into the kiln and fired to a certain temp. Once the desired temperature is reached the kiln lid is removed and small tissue bags are placed into strategically around the pieces inside and the lid is replaced. The tissue bags burn away and the chemicals begin to vaporize coloring the surface of the metallic glaze. It’s a serious safety hazard because of fumes are highly toxic, so full respirator masks must be worn at all times. The pieces are then cooled inside the kiln.