The clear glazes in this category are for applying over underglazes. The IN1001 and Pure Briliance are fully non toxic firable glazes. They fire at cone 06. They are dinnerware safe when fired at cone 06. They come in 4 oz, pints (16 oz), gallons, 3.5 gallons and 5 gallons. This is the recommended glaze for schools and institutions. This product, like all clear glazes requires 2-3 coats in its application. Dipping glaze in gallons and larger also available . This product, like all clear glazes requires 2-3 coats in its application. To Check Viscosity in the glaze Submerge a TL497 Viscosity Cup (available in our supply Misc. section) into tank and fill with glaze. As you lift cup from glaze, begin timing. Stop timing when the steady stream of glaze begins to break and only a few drops remain. A range of 19-24 seconds is normal. If glaze remains in the cup and reading is below or within this range, or if it takes longer than 24 seconds to drain, the glaze is too thick. Add small amounts of water as needed.