I have a large box of photos from the 1950s through the 1980s. Most of them measure 3 1/2 inch x 3 1/2 inch. Some of the 80s photos are 3 1/2 x 4 1/2 inch. I'm trying to find an economical storage system that will also help preserve them. I can't find any slip-in albums for this size (or any boxes) and I don't want to use blank books that require mounting corners. Any suggestions for storage?