Helen Frankenthaler trained at Bennington College, Vermont, becoming a leading exponent of American Abstract Expressionism. She developed a technique (‘soak stain’) of applying very thin paint onto unprimed canvases laid on the floor, partly inspired by Jackson Pollock. Her style in turn was imitated by others and was instrumental in the emergence of the abstract style of colour field painting. In the early 1960s Frankenthaler switched to acrylic paints, resulting in sharper, more richly saturated colour, also employing geometric shapes formed from stains and blots of colour against a white background. In 1966 she rejected a WIAC invitation to exhibit at the Whitechapel Gallery on the grounds she did not ‘show with any societies on principle’, despite three of her works having been lent previously by The United States Information Service to an international section, ‘Paintings from the USA’, in the 1960 WIAC exhibition.