Solar Rainbow is a highly fluid, dark gloss glaze with iridescent rainbow crystals. Breaks translucent. This glaze performs best at cone 6 but can be fired to cone 5. For best results, leave the inside or back of the form unglazed. Can be fired in a normal medium-speed firing with no special cooling schedule required. To take this glaze to the next level, use a controlled cooling schedule for increased crystal growth. These glazes are prone to running so we recommend stopping your glaze about half an inch above the foot. You can also use a drip tray or soft bricks to protect kiln shelves. Is this glaze food safe? Yes, but due to durability, these glazes are not recommended for food surfaces.