I finally watched this film... and I highly recommend it!
"HERB & DOROTHY tells the extraordinary story of Herbert Vogel, a postal clerk, and Dorothy Vogel, a librarian, who managed to build one of the most important contemporary art collections in history with very modest means. In the early 1960s, when very little attention was paid to Minimalist and Conceptual Art, Herb and Dorothy Vogel quietly began purchasing the works of unknown artists. Devoting all of Herb's salary to purchase art they liked, and living on Dorothy's paycheck alone, they continued collecting artworks guided by two rules: the piece had to be affordable, and it had to be small enough to fit in their one-bedroom Manhattan apartment. Within these limitations, they proved themselves curatorial visionaries; most of those they supported and befriended went on to become world-renowned artists including Sol LeWitt, Christo and Jeanne-Claude, Richard Tuttle, Chuck Close, Robert Mangold, Sylvia Plimack Mangold, Lynda Benglis, Pat Steir, Robert Barry, Lucio Pozzi, and Lawrence Weiner. "