KENNETH CLARK: CERAMIST WITH AN UNUSUAL BREADTH OF VISION

The ceramist Kenneth Clark died last month at 89. He occupied a rare position between studio pottery and industrial ceramics, running a small workshop and carrying out design commissions for architects and large potteries.  He taught at the Central School of Art (now Central St Martin's) and at Goldsmiths (whose ceramics course is long gone).  I always admired the breadth and openness of his vision.

As well as running his workshop, his design consultancy and teaching, Kenneth Clark wrote books for people starting pottery, which approached the subject in the systematic manner of the good educator.  His best-known book was The Potter's Manual, but I started on an earlier book, Practical Pottery and Ceramics, published in 1964 and still available on the second hand market. The introduction sets out his approach clearly and is so good that it's worth reproducing in its entirety.

A QUICK FLOURISH: ABSTRACT PAINTING ON TIN-GLAZED POTTERY

My medium is tin-glazed earthenware, but that doesn't matter much. I say it because some people are curious about how things are made.

Earthenware is a type of clay that's fired to about 1000 degrees centigrade By contrast, stoneware and porcelain are fired to about 1300 degrees. These figures are approximate, and there is a wide latitude. To be precise, I fire to 1100. Tin-glaze is a glaze made opaque with tin oxide. That was the traditional opacifier, but you can use other things as well.

Tin-glazed earthenware has a long history, originating in Iraq in the 9th century. It reached great heights in Renaissance Italy, where vases and plates were elaborately painted in the istoriato or story style. This phase of tin-glaze was called maiolica, probably because it first came to Italy from Majorca. The colours are from metallic oxides and the paintings are remarkable given that the painters couldn't get a red oxide. The nearest they got was iron oxide, which is basically rust, and that's the colour it makes on maiolica.