Kosuth writes to explain the basics of his works Titled (art as idea as idea), a series of blow-up photostats. He even includes a nail, taped to the paper, to show Castelli how the works should be hung.
Joseph Kosuth letter to Leo Castelli, ca. 1971. Leo Castelli Gallery records, circa 1880-2000, bulk 1957-1999. Archives of American Art, Smithsonian Institution.
Current copyright status is undetermined
Archives of American Art, Smithsonian Institution Washington, D.C. 20560