Films by Woody Allen, James Ivory, Ang Lee, Gordon Parks, Tom DiCillo, Spike Lee, Susan Seidelman and more have been spoken for, but others remain unclaimed and the trail has gone cold on many of them, said Steve Blakely, a former DuArt vice president who has continued to track down filmmakers since 2010.

It’s no real mystery why DuArt had all the movies. “Laboratories liked to keep materials because it meant more work for them,” Mr. Blakely said, noting the bouquet of emulsion still lingering in what was once DuArt’s 35-millimeter black-and-white lab. “In the laboratory’s mind, if the materials were here, it might get paid to make more prints.”

Most filmmakers, he said, finish a film and immediately focus on the next one. “Or they just lose track,” he added. “Or assume a producer took care of it. A lot of filmmakers I’ve contacted say, ‘I had no idea I left material there.’ Or ‘Didn’t my producer take care of that?’ But the main reason is they just move on.”

The dilemma at DuArt — where films awaiting adoption include “Mermaids and Pickles,” “Hoedown in China” and “Secret People: The Naked Face of Leprosy in America” — is a reminder of the transient nature of independent cinema, and the perils of independence itself. Hollywood lost much of its early legacy to the thinking that movies were disposable, and only later learned to take care of its own. Independent film, by its very nature, has had no system of preservation. People die. Companies close. There’s no database.

Even titles are no help, as Mr. Blakely pointed out. “Someone comes through here and says, ‘Look, there’s “Avatar!” ’ and you’re like, ‘No, no, look at the year on the box.’ ”