Precisely because film and photography capture the fleeting moment, they have been regarded as ephemeral and of little long-term value. Film is also materially ephemeral – because the earliest nitrate-based film stock was extremely flammable, negatives and prints of countless titles are now destroyed. Orphan films are films that have been abandoned by their owners or otherwise neglected and can include everything from amateur films, training films, and documentaries to censored materials, commercials, and newsreels.