I was curious how this would compare to QR codes:

TFA suggests that consumer scanners and printers can successfully work at a minimum of 200DPI. A QR code can store almost 3kB in a 177x177 matrix, which allowing for some padding nicely fits in a square-inch @200DPI.

This would allow approximately 285485 bytes per page before compression. For better error-correction, you could up the ECC in qr codes, or you could apply reed-solomon to the data before encoding. The latter has the advantage of correcting errors that take out most of a single QR code.