British painter and commercial designer. She studied at Goldsmith College (1949-52) and the Royal College of Art (1952-55), both in London. Between 1958 and 1959, she worked for an advertising agency at the same time as developing the Pointillism technique in her paintings. After these experiences, her interest returned to coloured painting and the optical effects it brought, causing the illusion of movement on the surface of the canvas. Around 1960, she explored the Pointillism of Seurat and between 1961 and 1965 restricted her palette to black and white with which, after 1964, she produced her most serene works. Later, she returned colour to her works and, in the mid 70s, through the use of white, managed to filter one colour into another, so as either to produce a third or to diminish the effect of the other two. In 1968, she received the first prize for painting at the Venice Biennale and, between 1968 and 1977, she took part in documenta 4 and 6 in Kassel. After a visit to Egypt in 1980-81, her works captured the spirit of the place, ancient and modern, and reflected the colours of the Egyptian landscape. Just like the painter Vasarely, one of her great sources of inspiration, Riley has contracted assistants to complete her paintings although she keeps a watchful eye on what is being produced.