Learn to make a metal clay firing box that won't mess up the inside of your kiln. No-Flake Firing Foil is a special high-temperature alloy that does not flake when heated to metal clay firing temperatures. The stainless steel firing pan that is most commonly used for firing metal clay was designed for cold and hot foods, not the red hot heat of a jewelry kiln. The extreme heat heavily oxidizes and expands the metal. As it cools, thousands of tiny flakes begin to pop off the surface, called "spalling". No-Flake Firing Foil is different. It's a special alloy that does not spall at extreme temperatures, so there's no mess and no flaking. Make any size box you need. We include written instructions with the product and include dimensions for box sizes you can make. Watch how easy it is to fold a box from this foil. Here's what you'll need: the foil, a 12" metal ruler, a wide burnisher (the wedge end of a ring clamp is perfect), a small ball burnisher or ball point pen for scribing, and a pair of household scissors.