This firing kit is excellent for firing bronze clay, copper clay, PMC PRO and Accent Silver. Fine silver clays can also be sintered using this kit. Firing fine silver in carbon is a good way to incorporate low-fire cubic zirconia, lab and natural gems (including diamonds) that would change colour or be damaged if fired on an open kiln shelf.Simply place 10mm of activated carbon in the tray, place your dried PMC creations on top of the carbon and pour more carbon on top of your artwork covering it completely without the carbon piling higher than the rim of the tray. Place the lid on top and you're ready for sintering, please follow the instructions that came with your PMC to determine the best temperature.In time ash deposits will build up on the activated carbon every two to three firings, to clean simply pour the activated carbon from one container to another, from a height of a few centimetres, two or three times and let the air carry away the dust. Best when done outside.Please note that this kit is heat-resistant up to 900°C (1,652°F); however, prolonged use at this temperature may cause deformation or severe damage. Under normal, non-high-temperature conditions, it can be used approximately 5 to 10 times, as advised by the manufacturer. Always follow the recommended firing instructions for your clay. Improper use may damage the kit or your work and pose safety risks. Use in a well-ventilated area with appropriate protective equipment.