recycled for their silver content, or destroyed in studio or vault fires. The largest cause, however, was intentional destruction. As film preservationist Robert A. Harris explains, "Most of the early films did not survive because of wholesale junking by the studios. There was no thought of ever saving these films. They simply needed vault space and the materials were expensive to house." Silent films had little or no commercial value after the advent of sound films in the 1930s, and as such, they were not kept. As a result, preserving the now-rare silent films has been proposed as a high priority amongst film historians. Because of the fragility of film stock, proper preservation of film usually involves storing the original negatives (if they have survived) and prints in climate-controlled facilities. The vast majority of films were not stored in this manner, which resulted in the widespread decay of film stocks. The problem of film decay is not limited to films made on cellulose nitrate. Film industry researchers and specialists have found that color films (made using processes for Technicolor and its successors) are also decaying at an increasingly rapid rate. A number of well-known films only exist as copies of original film productions or exhibition elements because the originals have decomposed beyond use. Cellulose acetate film, which was the initial replacement for nitrate, has been found to suffer from "vinegar syndrome". Polyester film base, which replaced acetate, also suffers from fading colors. Storage at carefully controlled low temperatures and low humidity can inhibit both color fading and the onset of vinegar syndrome. However, once degradation begins to occur, the chemical reactions involved will promote further deterioration. "There is no indication that we will ever find a way to arrest decomposition once it has started. All we can do is inhibit it," says the director of the AMIA (Association of Moving Image Archivists) board, Leo Enticknap. Film decay as an art form In 2002, filmmaker Bill Morrison produced Decasia, a film solely based on fragments of old unrestored nitrate-based films in various states of decay and disrepair, providing a somewhat eerie aesthetic to the film. The film was created to accompany a symphony of the same name, composed by Michael Gordon and performed by his orchestra. The footage used was from old newsreel and archive film and was obtained by Morrison from several sources, such as the George Eastman House, the