You can encrypt the wallet with AES256, encode the wallet in BASE64 using some easy-to-parse computer font such as Courier New or System (they must be monospaced so they can be perfectly read again using OCR), and then print out the characters onto a large number of sheets of paper. Then you save the AES key and IV as qrcodes. Store all materials in a confidential place such as inside a safe.
I tried this but my Base 64 encoded file has almost 90,000 characters in it and the software (NOTEPAD++) I was using to do this test couldn't handle that. When I printed it to a pdf file, it only printed the first 4 pages. The OCR tool seemed to scan in those 4 pages ok but I have no idea if it really did since I can't really know until I decode the entire thing but to do that, I need the entire pdf file scanned. Not just the first 4 pages.
When you want to access the file again, read the papers in with a scanner, strip all whitespace and then decode the AES256 with the key and IV you have independently scanned. Requires a lot of paper, but it works.
If I can get to that point. But I have a feeling it's going to require 27 pages of printouts. Unless there was a way to shrink the printing size significantly.