With the use of good laser printer the author claims that you can save up to 500,000 bytes of uncompressed data on a single A4/Letter sheet. To restore your backups you just need a scanner.
To answer your obvious question "Why use that program?" I'll quote from authors site:
"You may ask - why? Why, for heaven's sake, do I need to make paper backups, if there are so many alternative possibilities (...) The answer is simple: you don't. However, by looking on CD or magnetic tape, you are not able to tell whether your data is readable or not. You must insert your medium into the drive (if you have one!) and try to read it."
Site: PaperBack 1.00