Stoneware crystal glazes are developed to provide sparkling crystal effects that spread and open on the surface during firing. Each firing result will be unique and can vary, among other things, depending on how the item is placed in the kiln.
The crystals in the glaze often settle at the bottom of the jar and therefore need to be thoroughly mixed before use. It is recommended to stir well both before the first application and between each layer, so that the crystals are evenly distributed. Untreated tools, such as a palette knife, can be used for stirring.
To reduce the risk of running marks, crystals should be avoided in the lower part of vertical shapes, as they melt more than the base glaze itself during firing. While the glaze is still wet, a fan brush can be used to spread the crystals evenly over the surface. Over-application or too high a concentration of crystals can lead to imperfections such as pinholes or running.
When storing, it can be beneficial to store crystal glazes upside down, so that the crystals are more easily distributed evenly for the next use. As always, it is recommended to test the glaze on test pieces before use on finished works. Follow the manufacturer's instructions and use standard precautions when handling glazes.