The paintings of Morris Louis mark an important development in the exploration of colour and light which can be traced back through the history of modern art to the Impressionists and beyond to Turner at least. In particular Louis exploited the technique of pouring paint onto unsized and unprimed cotton duck canvas so that it soaked in. The effect was of dyed cloth rather than paint on a surface. This created an unprecedented purity of colour effect with no interference from surface texture created by brushwork. It was this technique, allied to Louis's lyrical sense of colour and equally lyrical and often dramatic sense of composition, that aroused the enthusiasm of the critic Clement Greenberg: 'The more closely colour could be identified with its ground, the freer it would be from the interference of tactile associations ...' Louis, Greenberg continued, 'began to feel, think and conceive almost exclusively in terms of open colour. The revelation he received became an Impressionist revelation.' The essential simplicity of Louis's painting was usefully pointed out by another critic, Amy Goldin: 'Louis was never a difficult artist. His paintings are not problematic. They are voluptuous and restrained and for making you happy ... For these paintings talk is irrelevant.' And the art historian Robert Rosenblum wrote of 'sheer visual assault ... breathtaking in its direct sensuousness ... languid expansive beauty that newly evokes the exquisite hothouse atmosphere of the most precious Art Nouveau gardens.' It seems clear that Rosenblum is here thinking of Louis's paintings of the type of 'Alpha-Phi', which are known as 'Unfurleds', where the separate bands of colour do indeed have a flowing organic quality that evokes the sensuousness of Art Nouveau, with its forms derived from often exotic plants and the lines of a woman's body. Louis's bands of colour have this quality, of course, because they directly result from the natural flow of the liquid paint down the surface of the canvas. 'Unfurleds' like 'Alpha-Phi', where the bands of colour are placed across the lower corners of the huge canvas, are particularly breathtaking in their effect of an infinite empty space bounded by vibrant colour.
Simon Wilson, Tate Gallery: An Illustrated Companion, Tate Gallery, London, revised edition 1991, p.230