Here is my approach, something I've shared with others previously. I like to store my cabinets in three ring binders, slid into magazine albumn pages, within an 8x10" top loader and soft sleeve insert. Working through this backwards . . .
1) Custom made soft sleeve inserts. I haven't had to order these in years but I believe they (Atlantic Protective Pouches) are still taking orders. I ordered 3mil mylar polyester sleeves that measure 7 7/8" wide x 11 1/2" high, open on one short side (this is a custom size that works well for large assortment of cabinets that I like to stick in 8x10 top loaders). I usually cut these down to only 9 7/8" high so they can fully fit within an 8x10 top loader.
http://www.atlanticprotectivepouches.com/
2) I then slide #1 above into an 8x10 BCW Photo Top Loader
http://cgi.ebay.com/25-BCW-8-x-10-Ph...item53e1f03870
3) I take #2 (& #1) and slide them into a BCW 1 Pocket 8 1/2 x 11 Magazine Album Page
http://cgi.ebay.com/100-BCW-1-Pocket...item5ade811987
I arrange 1, 2, & 3 such that it would be difficult for a splash of water to reach the card by alternating the open end of the sleeve/top loader/page. That is, the open side of the sleeve is at top of the cabinet while the open side of top loader is at the bottom while the page is open at top. So water would have to come in from the top of the page and reach the bottom where it could enter the top loader but then has to travel back up to the top before it enters the soft sleeve. Lastly, I store the pages in a zippered 3 ring binder.