[keybpo]

A small thermal printer would probably be direct thermal, which uses a heat head and heat sensitive coated paper. This fades away naturally, even if kept in the dark. Glue from tape will accelerate it, in case you're thinking about it to protect from abrasion.

There's also thermal transfer printers, which use a ribbon as "ink", similar to typewritter. These labels can endure much harder conditions, like scratches, high temperatures and fade. They're used all over the industry. But these aren't usually small printers and have a high cost. At that point I think you have better solutions on printing services (I understand if you don't want to have the files outside of your environment, though.)