03 August 18 Roy Lichtenstein, Knock, Knock Poster, 1975, line-cut, in black, on Arches paper, 65.4 x 47.6cm. © Estate of Roy Lichtenstein/DACS/Artimage 2018 Roy Lichtenstein, Knock, Knock Poster, 1975, line-cut, in black, on Arches paper, 65.4 x 47.6cm. © Estate of Roy Lichtenstein/DACS/Artimage 2018 0 Comments