Andy Warhol's painting of Marilyn Monroe was made soon after her suicide in August of 1962. The basis for the painting was a publicity shot.
According to Web Exhibits, the publicity shot used as Warhol's basis for his Marilyn Monroe artwork was taken by Gene Korman. It was used for a 1953 film called "Niagara." Warhol's painting was an example of silkscreen printing. Warhol claimed, "I wanted something stronger that gave more of an assembly line effect. With silkscreening, you pick a photograph, blow it up, transfer it in glue onto silk and then roll ink across it so the ink goes through the silk but not through the glue. That way, you get the same image, slightly different each time."