sentences:  Described by its publisher as "the first three-dimensional magazine," each issue came in a customized box or folder filled with materials in a variety of formats, including booklets, "flexidisc" phonograph recordings, posters, postcards and reels of super-8 movie film.Many of the leading figures in contemporary North American and British art and cultural criticism were editors, designers or contributors to "Aspen".The magazine has remained of interest to students of the artistic ferment of the late 1960s; extensive documentation of "Aspen"'s contents is available online at UbuWeb.