We stock a variety of different styles of firing cones made by Orton Ceramic. These cones are made of a special type of compressed glaze material that melts and bends at specific cone ratings which is a reliable gauge for confirming your firing results. We recommend utilizing 3 cones of varying ratings across your desired target (if target is Cone 5 then you would want to add a Cone 3 and 6 to bracket the target, this would tell you if your kiln over/under fired).