7″ X 13″ X 5/8″ (177 mm x 330 mm x 15.8 mm) half kiln shelf. Half shelves allow you to stagger the height of each layer in ceramic firings. Line up two half shelves so that one is about 2″ (50 mm) higher than the other. This improves air circulation in the kiln. Protect your shelves with kiln wash (or glass separator, if you fuse glass). Paragon’s cordierite shelves are volume-stable.