Sagger firing involves getting each piece to react only to specific material. Organic combustible materials, such as seaweed banana peels an saw dust, or reactive chemicals, copper, stainless steal, cobalt and ferric chloride are selected for each pot and applied by spraying and or brushing. Loose materials are placed on the piece and secured in place by wrapping the piece in aluminum foil. Each piece is wrapped in several layers of aluminum foil to protect it from the materials and chemicals on the other pots. Pots can also be placed in metal bins or premade pots that fit around the piece.This ensures that the surface of the piece will only react with the materials inside the sagger.