Most philatelists have photographs, slides, negatives, and related photographic items.
Most materials used for storage, especially plastics, have been discussed previously. Some of the commercial albums available over the past few years have been a disaster to those who used them. Phthalate plasticizers migrate from PVC and form yellow oily droplets on slides. Slides and films stored in PVC pockets or enclosures will have a waxy film on their surface. PVC film will degrade photographs by producing acidic hydrogen chloride.