Glaze Recipe: Roelof Uys at the Leach Pottery

The iron-rich stoneware glaze known as Tenmoku has been used by studio potters in the West for many decades and was likely first introduced by Shōji Hamada when he and Bernard Leach began working together in the early 20th century. Although it remains one of the most iconic glazes and a staple of makers who work in the Leach tradition, it has often been viewed as old fashioned and synonymous with the standard dismissal of ‘brown pots’ levelled by its detractors. Although I agree with some criticisms, I feel that these opinions are often rooted in a lack of understanding about the subtleties and beauty of this glaze, coupled with a glut of bad examples.

The Tenmoku that we use in the Leach Studio was given to us by Warren MacKenzie during his residency in 2013. I had started my role at the Leach just a few months earlier and was beginning work on a Standard Ware range through which I wanted to reflect our heritage, but with a contemporary feel. I also wanted the range to be a good vehicle for training our apprentices in the various skills necessary to become skilled studio potters.

One of the first things I learned about Tenmoku is the importance of application. All our pots are dipped in large buckets of glaze with great care given to even application; the thickness of the glaze is crucial, and we use a hydrometer to determine the correct ratio of glaze material to water. I sometimes dip or wet part of a piece before glazing, which will cause that area to absorb less water and leave a thinner covering of glaze that can be used to create a more varied overall aesthetic. One of my favourite qualities of this glaze is the way it breaks from deep black to a beautiful rust colour over textured surfaces and sharp angles.