For postcards I use plastic pages with 3 or 4 pockets...mostly 4, which I get at a local coin/sportscard shop. I've also bought a few at flea markets.

Do you collect full matchbooks or just the covers? For just covers, I get 6 pocket pages from the same shop. For full books, we have a few sets of plastic drawers that I found at Target. I put the matchbooks in small ziplock bags, or in postcard-size plastic bags. I store most of them open, so they don't get stressed from being opened and closed...some of our older books are pretty fragile.

It would be better if the storage was airtight tin, but...

I use a sticky tab to put the casino name on each bag, then store them alphabetically

I store 4-6 common books in the same ziplock

This drawer has odds & ends...non-casino books, oversize books, a few that are in rigid holders, etc.