Furthermore, the chemical process, de reaction of the different chemicals used in the photographic materials and for development fixing etc., never stops. These factors make photographic preservation a very complex business. Considering the many threats to their existence, it is a small miracle that thousands of these fragile items, many even dating from the earliest days of photography, have survived the wear and tear of time. Because of the continuing chemical process within the photograph, all photographic materials will inevitably deteriorate over the years. This steady decay may be accelerated by factors like high or fluctuating temperatures and humidity, pollution, and handling.
Some photographic materials start fading only after a few years' time.
This was already a major concern in the early days of photography. In 1855 the Royal Photographic Society in London published a paper on the effects of certain chemicals and environmental factors on the stability of photographs on paper, after complaints in the popular press. Because of their complex structure photographic materials require careful handling. Since prevention is better than cure it is important to take certain measures to extend their lifetime. Today we know more about the behavior and stability of modern photographic materials.