Countless negatives for acknowledged classics are gone forever. Such beloved films as The Magnificent Ambersons , Dr. Strangelove , The Ox-Bow Incident , and Stagecoach have had entirely new prints struck, with the negatives lost to the ages. There are plenty of things that have come together to create this situation. Nitrate-based celluloid stock was the standard before 1950 or so, yielding a shimmering image that gave films from the day their distinctive look. Unfortunately, nitrate reacts with air to produce nitric acid, corroding films as they sit in storage.
Nitrate stock is also highly flammable and nearly impossible to extinguish once it ignites.
In plenty of instances, films spontaneously combusted as they sat in the cans. The negatives of Singin' in the Rain and Citizen Kane fell victim to nitrate fires over the years. Nitrate was replaced by safety stock in the 1950s, but safety stock came with its own problems. Hence, this film will forever exist only in a degraded state. For years, the industry's answer to many issues of film storage was to transfer the movie onto a master videotape, simply discarding the original or leaving it to rot.