Aquatint etching by Robert Morris, signed and numbered in pencil, edition: 150, AP 20. Full title on the upper left corner: "Separate Walkways: The Wardens Above, the Inmates Below from In the Realm of the Carceral." Robert Morris was a major theorist in the Minimalist movement. Printer: Styria Studios, NYC. Publisher: S & A Lithographic Plates, NYC. Reference: Fig. 30 in "Robert Morris: Estampes et Multiples 1952-1998, Catalogue Raisonne" by Christophe Cherix, Geneve et Chatou 1999. Unframed.