I don't know what they are called, but at some point in time, I had these flipper things. They fit 4x6 photos (and I think they sold 5x7 ones, too, that might fit your cards). They had several layers of protectors that went down the page for the photos, and the adhesive was at the top only, so you could "flip" the photo up and see what was on the back. I think they were made by 3M. I'm not sure, though. I can picture those darned things in my mind, too, but can't think what they were called.