I'm considering making cold paper wallets (for multiple cryptocurrencies) for offline storage in a safe deposit box. Before accessing the safe deposit box, my identity is checked and I must show my key, so I consider storing the paper wallets non-encrypted.
They are a lot of tutorials on how to generate a wallet on an offline computer, but I'm searching for an efficient way of transferring the wallets to the paper.
Here are the options I have considered, and I would like your opinion.
In a technical point of view, handwriting the wallet key seems secure but tedious. I'm not very confident about reading my own handwriting in ten years, especially in base56 , not talking about my children reading it.
Low-cost laser printer
Buying a $60 printer that should be supported by the offline computer. I think that kind of offline printer will be unlikely to store my private keys and even more unlikely to transmit them.
Buying a second hand typewriter and typing the key on it. Seems pretty secure and relatively easy, if the key can't be extracted from the ribbon.
Label printers can probably work without a driver, just by echoing the key through the serial port, but thermal paper won't last enough, thermal transfer can be read on the ribbon and matrix printers are expensive.
Embossing label maker
I'm pretty sure that this one can't be hacked and can be read by anyone in thirty years, but they don't have upper and lowercase required for base56. Writing the key in hexadecimal can be a solution.