Meet Piper: your first bitcoin paper wallet printer

Thermal paper is by far the last medium I want to store a wallet on...

I wonder why the creators chose this. Does it allow for a smaller footprint?

Yes, the thermal printing mechanism is very simple. You need a printing head, which you can get as pre-build module, and you need a mechanism to feed the paper.

Alternatives are for example thermal transfer printing method, where you have a roll of paper and a roll of ink on a film that gets transfered over to the paper on the areas that are heated. Technically this is more complex, but on a product like this, they saved on thew wrong end by using thermal paper.

Couldn't be a printer with same footprint be build with laser printing? If you keep the resolution low and got the time and money for the research, It should be possible I think.

Yep. I've had receipts turn black just sitting in a drawer. This is certainly not what I'd want to store my currency on.

Could this be useful transfers arranged through a service like https://localbitcoins.com/ ??

That'd be my second: http://www.ollydbg.de/Paperbak/index.html