'I don't paint light. I present a colour situation which releases light as you look at it.'

From 1974 until 1979, the fundamental unit of Bridget Riley's paintings was the curve. A broadening and a deepening of Riley's understanding of the relation of colour and light can be discerned in her curve paintings. The key to this is the role of the curve in creating a more pliable, less assertive structural armature so that occasionally the effect is as delicate as stained glass. This is also a structure in subtle movement. The eye follows the course of a curve and loses the thread as the shapes begin to fuse, dissolving like a rising haze of heat or undulating like ripples on the surface of water. These effects are non-descriptive yet tantalisingly evocative, recalling the patterns and rhythms of nature. They are also deeply expressive.

Before commencing the curves, Riley had observed: 'My paintings are, of course, concerned with generating visual sensations, but certainly not to the exclusion of emotion. One of my aims is that these two responses shall be experienced as one and the same.' The curve paintings include some of the most serene and emotionally radiant that she has ever painted, an implication that blossoms in the connotations of poetry and music contained in some of their titles. The paintings draw the eye into an intoxicating optical experience. The simultaneous contrast of adjacent colours, and the evocation of fugitive colours resulting from optical mixing, build cumulatively. They take the paintings within a hair's-breadth of their overall colour focus being lost. Yet always, within this dissolution, a sense of order remains.

Abridged from Paul Moorhouse's introductory text to Bridget Riley's Tate Gallery retrospective catalogue, 2000.