This specially formulated product can be fired up to Cone 10 (2381° F.) on porcelain and stoneware. Just add any high-fire clay or slip to the jar contents, stir it and apply the mixture to the break or crack with a brush. Keep the pieces together until they are set and the application is completely dry. Clean the piece, then fire or re-fire in your kiln. The piece can then be glazed over once it has been fired. This product comes with 18.9 grams of mender in a 2 oz. jar. Once you add your slip or clay, it creates 2 oz. of mending material. This will last for multiple applications and has an indefinite shelf life.