I talk about digital photography here most of the time, but I’ve recently been scanning some old photos from the 1930s (the photo above is NOT one of them) and it gave me the idea to talk about preserving old pictures.
I think the best way to preserve old photos is to scan them and then make a copy of the scan onto both hard disk and DVD. Additionally, making a print is, always has been, and always will be a viable archival method for preserving old photos.
Beyond that, if you want to store either the old, original print or the new one, there are some things you should know.
1) Avoid garages, attics or basements. Since these places rarely have insulation or controlled temperatures, they are terrible places to store old pieces of paper. Temperature swings are harmful to photographic papers. Consistent temperatures in the 65-70 degree range are best. These places are also breeding grounds for pests. Rats for instance love to eat paper. So do most bugs.
2) If you’re making new archival prints, only use top-quality acid-free, archival paper to print on. It makes a difference. This isn’t the time to go to Office Depot looking for a bargain.
3) Avoid humidity. If you can, keep relative humidity under 50%. If you’re storing actual photographic prints made with a photographic process, high humidity could cause the emulsion to separate from the base of the photo.
4) Store pictures in plastics like polyester, mylar, plypropylene and tyvek. Avoid wooden boxes since they are rarely acid free.
5) Wear artists’ gloves when handling photos and negatives. They keep the oils on your hands from damaging the photo materials.
Note, this list is not complete, but a good starting point for anyone interested in the topic.