Although you seem to forget that my file is almost 90 kilobytes. Checksums is an additional overhead and software complexity that most people probably don't have the technical ability for. But I'm intrigued.
The beauty of using an "external" checksum is that you don't have to use it: you can still type all 90,000 characters manually, but if you make a mistake, using the checksum will make it easier to find where you went wrong.Quote
I wish I could test out this method
That's easy: print 1000 bytes, type them all, and see if they're the same.Quote
yeah I know about md5sum but do you think that's the best type of checksum to be using? It doesn't attempt to fix any errors and it's pretty huge. 
I mean my 25 page file I could legit see it balooning to 40 pages after this fiasco!
You don't have to add 15 pages of checksums: you can also do one checksum per page. It depends on how accurate your OCR or typing skills are. I mean my 25 page file I could legit see it balooning to 40 pages after this fiasco!Error correction would be better, and that easily puts you back at QR-codes again (where you can choose the level of error correction).
I still think printing 90,000 bytes as a backup is a terrible idea though
