“Ideas are not the only thing Hollywood recycles: The thousands of prints left over after all those blockbusters have run out of steam at the nation’s multiplexes have sparked a thriving industry that helps transform old film into other products, including polyester fabric. Last year’s ‘Harry Potter and the Chamber of Secrets, for example, required 8,400 prints for the U.S. and Canada alone. For that three-hour movie, the total for those prints amounts to about 29,000 miles of film.”