What causes your treasured photos to become damaged in the first place? Obviously, the storage method (or lack thereof) plays a big role. A shoebox in your closet doesn't count as a bonafide storage method. Photos are delicate by nature, and they should be protected like any other valuable. The older and more precious the photo is, the more care should be taken to curb damage by preventable elements, such as light, excessive heat or cold, bug infestations, fingerprints, water damage and mildew.
Sometimes, photo damage can be difficult to prevent. Poor processing by the developer in the first place can cause photos to be less resilient over time. Also, the materials utilized during development, like dyes, inks, chemicals and the gelatin surface of a photograph, can interact badly, resulting in fading or spotting. Photographic paper or mounting boards sometimes contain acid, which is known to cause long-term damage on delicate photos.
Ironically, even those of us with good intentions can do more harm than good by removing old photos from albums. Peeling back a photo from a sticky page can cause irreversible cracks that even the best restoration expert will have trouble fixing. The best bet in this situation is just to leave the photo alone and opt instead to store the album correctly.