Pottery Clay: Best Mix- BMix - BMX - Mid Fire Cone 5-7 - Rocky Mountain Clay Smooth white mid fire clay. Great for wheel throwing or hand building Non toxic and safe for kids/classrooms Great for potters, teachers, classrooms, studios. Economical all purpose clay BMX (Best Mix) Clay is great for a wide variety of glazes. It ranges in firing color from a soft white to a light gray color, perfect for the wheel or hand building projects.If you are searching for a light white throwing body that is easy to use and accepts a wide range of your own glaze formulas or commercial glazes, then this is the clay for you. We have blended the optimum percentage of clays and raw materials to achieve a silky soft white (no iron spots) clay that can be used on the wheel or with hand building operations. Depending on the amount of reduction kiln atmosphere BMX fires white to a light, stormy sky gray. Mixed by Rocky Mountain Clay