Refractory slip coating applied to top surface of kiln shelf to protect from glaze runs. For all but salt and wood firings, 50-50 kaolin and silica. For salt and wood, 60% alumina, 30% kaolin, 10% ball clay. Source: Clay: A Studio Handbook
Sign up for your FREE subscription to the Ceramic Arts Daily Newsletter and we will give you How to Add Color to Your Ceramic Art Free!