This is a utility to generate paper backups of GPG keys, including ones with subkeys. These backups include hand-typeable hex, and a (huge) QR code.
There are sample PDF files for a test key located in /samples. The test key they represent looks like this:
sec rsa4096/0x505046B10F254146 2018-02-04 [SCEA]
Key fingerprint = E15D A5E3 414D 83D6 CDDA A578 5050 46B1 0F25 4146
uid [ultimate] test test (If this key leaves my local machine, I've screwed up. Please delete it from any listings) <test@test.test>
uid [ultimate] test test
ssb rsa4096/0x3EA6EA6016656732 2018-02-04 [A] [expires: 2068-01-23]
ssb rsa4096/0x9D3522052CC8DFAB 2018-02-04 [E] [expires: 2068-01-23]
ssb rsa4096/0xAC2FFAAC06A43B6C 2018-02-04 [S] [expires: 2068-01-23]
Try recovering that key to see how it works.
This is designed to run under Linux, and needs the gpg utility, bash, and latex installed.
Run the generator by finding the fingerprint of the key you want to export, and calling it like this from the directory:
cd latexgpg
./latexgpg <key-id>
That is:
./latexgpg 0x505046B10F254146 for my test keys