The Effect of Feldspar Composition on Sanitaryware Glaze Performance

Glazes are often used for practical reasons to enhance aesthetically or technically traditional ceramic whitewares such as sanitaryware and so there is little debate regarding the standard definition for a glaze which is "a vitreous substance fused on the surface of pottery to form an impervious decorative coating" (Oxford University Press). However, to maximize the properties of a typical sanitaryware glaze system it is not only necessary to understand the science around glaze formation but also the interaction of key glaze constituents. Often these can significantly affect final glaze properties. In this study we have found that whilst most feldspars can be used to produce glazes only a limited number have significant benefits in terms of fusibility, reduced defects and improved surface finish.