I like to make things in which the elements are distinct and in which each decision is sure and unambiguous. My elements are squares, triangles, lines and other simple shapes. Their properties of colour and various surface qualities, together with such things as levels of relief, the distance between things, etc., constitute my palette. Mostly I work by combining these elements – either physically or in my mind. I arrange and re-arrange my basic stuff until I have assembled an order that either pleased me or satisfies the pre-conditions of the work.

Two principle interests underlie my work. One is the physical medium of the relief itself and the other is my interest in mathematical structures. They may be fundamentally different, but they are not incompatible. It seems to me that the discreteness, the separability of the parts of the relief provide a physical counterpart to the sets of elements of a mathematical system.

Four Artists Reliefs, Constructions and Drawings, Victoria and Albert Museum, 1968.