Not sure what I would do with absolutely naked stamps. I LOVE the THIN Cling foam. Store Hundreds of stamps on Laminated Cardstock in heavier page sleeves standing up in a box/basket. Two baskets fit in a box w/handles that used to hold Creative Memories stuff. SO much less bulky than notebooks, and EASY to thumb through.
I suspect that propylene glycol that is in flexible plastics may also leach into the tacky surface of cling foam or stamps, and react w/it. (It's a issue w/many of the pharmaceuticals I deal with).
So far, none have lost tackiness. Will be VERY sad if they do. I have seen some gals use the Tac-N-Peel, but it seemed expensive. Might consider that if they really lose tackiness.
I ABSOLUTELY LOVE my storage system, and would be glad to share pics.