They definitely make supersized top loaders for the ad. I keep some of my autographed 8x10 and 16x20 photos in them. I even have a huge lithograph in one and it's closer to 30" x 40". So you should be able to find one in the size you need. Only downside might be having to buy a pack of them, though you might be able to find a shop for individual ones, or possibly even on eBay.
Collecting John Stockton, Karl Malone, Ivan Rodriguez, Gary Carter & UF player rookie year cards. Plus Jedd Gyorko rookie and prospect cards.
Jedd Gyorko 2010-2013: Have 329/419 including 1/1s
Wantlist: http://sites.google.com/site/sportscardsite/set-needs/
Jedd Gyorko 2010-2013: Have 329/419 including 1/1s
Wantlist: http://sites.google.com/site/sportscardsite/set-needs/