He raised, in unprecedently acute form, questions of how reality may be represented in art which have been of central concern to modern artists from Courbet on, and which were central to Pop Art. His extreme position on such issues is one important element in his art, but there is more, since Warhol was possessed of an acute vision of the major themes of human life - food, sex, death, money, power, success and failure - as these were manifest in the surface appearances of his own times. Above all perhaps, he was unerring in his choice of images which encapsulated these themes. His choice of Marilyn Monroe and of a particular photograph of her, is a case in point. Campbell's Soup, as exemplary of convenience food, is another [see Tate Gallery P07242]. As in other Pop Art, but again to a much more intense degree, these images are presented in Warhol's paintings in a detached and dispassionate manner, as a series of silent questions for the spectator to make of as much or as little as they will. Warhol's painting took on its mature edge when, following the logic of his printed source material, he began to adapt the silkscreen printing process to painting. Silkscreen is a form of stencil, much used by artists for print-making, and normally prepared and printed by hand. However, the image can be put on the screen photographically, which is what Warhol did, thus mechanically reproducing his source. In 'Marilyn Diptych' this was a still photograph of Monroe in the 1953 film Niagara. Marilyn Monroe died, from an overdose of sleeping pills, on 5 August 1962. Between then and the end of that year Warhol made at least twenty-three silkscreen paintings of her. In them he retained the handprinting of the silkscreen onto the canvas and, as can be seen, constantly varied the image by changes in the registration of the different colours or the amount of paint put through the screen. In the right panel of 'Marilyn Diptych' he has produced effects of blurring and fading strongly suggestive of the star's demise. The contrast of this panel, printed in black, with the brilliant colours of the other, also implies a contrast between life and death. The repetition of the image has the effect both of reinforcing its impact and of negating it, creating the effect of an all-over abstract pattern.
Simon Wilson, Tate Gallery: An Illustrated Companion, Tate Gallery, London, revised edition 1991, p.243