Potclays Reactive & Low Stoneware Glazes

Reactive glazes (codes beginning 2320-) can be used as low temperature stoneware glazes fired between 1180 and 1230C, or as underglazes - covered with higher temperature glazes - which combine during stoneware firing to give excellent combination effects.

Reactive Slip 2394-01M is intended for use underneath various stoneware glazes to give varied reduction effects in electric firings and can be applied to biscuit or leatherhard clay. 

'Mineral' glazes (codes beginning 2350-) fire in the range 1180-1230C and are semi-matt, becoming shinier with increased temperature. Through trial and error in our glaze testing, we identified that a ‘drop-hold’ firing schedule suits this range of glazes and promotes crystallisation. Results on a horizontal surface will be different to those on a vertical surface, and crystallisation is affected by application thickness. On the attached image of White Topaz, you can see the difference between a thin application and thicker application on a test tile fired horizontally. The firing schedule we use here is 110c/hr to 1100c, 60c/hr to 1200c, drop to 1180c and hold for 15-20 minutes. 

All stoneware glazes are leadless and suitable for dinnerware, but for practical reasons we don’t recommend matt or special effect glazes are used on surfaces in direct contact with food or drink due to the possibility of staining and/or bacterial growth.

Powdered glazes, once mixed with water according to the recommended guidance, are suitable for dipping, pouring or spraying onto the piece. They are not suitable for brushing-on without addition of a glaze binder such as Pehatine. If brush-application is intended, we would recommend you select one of our ready-mixed brush-on glazes instead.

Artistic/special effect glazes usually require a generous application to achieve the desired effect. Please note the individual product descriptions for product-specific guidance. Some special effect glazes can melt/flow considerably during firing so please take all necessary precautions, especially with regard to protecting your kiln furniture (stilting, batt wash, use of 'cookies' etc.).

For glaze preparation advice please see the main powdered glaze category header here.