A film specialist checks film and writes recommendations to the clients about actions to keep the film in a good shape at Pro-Tek Vaults on May 7, 2024 in Burbank, California. Reels of film and the Hollywood stars who fill them share one common enemy: ageing. But while an actor can go under the knife or get a bit of filler in an effort to stay young, it's a one-way street for film, which eventually starts to break down into its original -- rather prosaic -- ingredients. "Film base is actually wood pulp and acetic acid in its simplest form," says Tim Knapp of California-based film preservation specialists Pro-Tek Vaults. (Photo by VALERIE MACON / AFP) (Photo by VALERIE MACON/AFP via Getty Images)