Thin plastic covers work just as well for me in the safe deposit box. The bigger the slab space becomes, the more expensive safe deposit box room it takes. It would be nice of the auction houses used these. That's where slabs get scratched up the most ... in and out of the boxes ...
I used to use acid-free heavy art paper to separate slabs in the boxes. Then at FUN I bought about 500 of those plastic sleeves from Wizard and they work well. Fit PCGS, NGC, CACG, ANACS and ICG slabs. Although they do take up a little more horizontal and vertical space than the paper spacers. But now I'm not worrying about any chemical releases from the paper.
No joke, they already exist and I've seen them in the wild and I actually really like them. I can't stand scratched slabs, especially when I just had them Reholdered because of scratches. PCGS and CAC are both very rough on slabs. It was a vest pocket dealer that had his personal coins out at a coin show in Augusta, Maine and he had some really nice toned Morgans. Oddly I was the only person in the show that really showed any interest and I talked to him literally for 2 hours. Anyways, instead of having his nice slabs all scuffed up ruining The view of his nice tone coins in his personal collection, He had them in really nice zircon holders. They didn't add too much bulk and I would personally definitely do this with my collection if I was going to let the general public handle the coins. I'm not sure if this is actually what he had, but you get the idea.
