Scotch double-sided tape has been recommended here a few times, so I bought a roll and used it in a UN album to hold some larger items, UN mini-sheets, that were flopping around too much on their album pages. All of them -- All of them -- came loose within days. The tape was attached to the back of large mounts, and then to the page itself. The side that came loose was the one attached to the mount. So I take that to mean that double-sided tape will not hold onto plastic mounts well. So scratch that option. But maybe smaller mounts wouldn't stress the tape as much, so they'd hold individual stamps . . . ? Not sure.
As for glue sticks, they might work on mounts. But as with the larger mounts and double-sided tape, I think gluing plastic to paper seems unlikely to work. But it's worth trying, and I'll do that next chance I get.
The "post-it" notes type of glue, a glue that holds well until you want to peel it off, might not work on stamp mounts. But it would be an improvement if it did. If one of you could just hurry up and invent a removable glue that holds stamp mounts on pages well, I'd appreciate it very much.
