Crystal glazes were designed to mature at cone 06/05. Apply to shelf cone 04 bisque. Shake jar well and stir during the application process. Apply 3 coats with a fan brush, allow to dry between coats. Avoid placing crystals towards bottom of ware to keep them from flowing onto the kiln shelf during firing. Crystal Glazes can be fired to higher temperatures. The crystals in the glaze will melt when fired, which may create a textured surface. As that surface may be difficult to properly clean if in contact with food, we recommend crystal glazes to be used on decorative ware. Jungle Gems ™ and Crystalites ™ glazes are certified AP® nontoxic, with the exception of CG 707 Woodland Fantasy and CG 713 Peacock Green which require a caution label, CL® , due to soluble copper.
Many Mayco low fire (cone 06) glazes can be fired to Cone 6. A description of the Cone 6 results are on the product label. Always test and protect your kiln shelves when testing a glaze to a temperature higher than the recommended firing temperature. At Cone 6 place them only toward the top of a piece because they really run but the results can be beautiful.