I borrow the term from the flatbed printing press—‘a horizontal bed on which a horizontal printing surface rests’ (Webster). And I propose to use the word to describe the characteristic picture plane of the 1960s—a pictorial surface whose angulation with respect to the human posture is the precondition of its changed content.
post edit: Link / its a pdf. figured he was (AW). i cant post a comment yet w new system. duh.