pdflatex --shell-escape gpgbackup.tex to produce a pdf that you can print and lock away.
In order to recover the key, you will have to scan extract individual QR Codes with names
IMGd.png, as given in the name of each figure, then run the recovery commands.
NOTE: The above command WILL leave some artefacts in
/tmp which should be removed using the command
PS: Original formula for this gist was from @costrouc.