From a prior post inquiring about creating this exact type of device:
Thermal resin (uses paper + ribbon) will last "forever". The resin will likely last longer than the paper.
Thermal (uses only chemically treated paper with no ribbon) will be unreadable in a matter of months (days if exposed to higher temps).
Some printers can do both, some can only do one or the other.
So from your FAQ you show:
Currently, the image will last 3 years but we are in the process of acquiring bulk-quantites of specially coated, archive-quality paper to use with it which will last over 20 years.
First of all, thanks for the feedback! I wasn't aware of that post, if I had seen it I would've been more clear about the life of the image.
Anyway, I was also concerned about the life of the image. I made sure to buy "long life" thermal paper, but "long life" wasn't really specific enough for me so I emailed the distributer where I bought the paper about image life, and this is what they said: "Stored under the proper conditions (In a cool, dry environment with no exposure to light) the product will last generally 3 years or more."
I'm looking into buying a better type of paper though, which will last 20 years. Here's an image of the manufacturer's spec sheet:
http://piperwallet.com/newpaper.png
What type of printer will you use?
It's a direct thermal printer (not thermal transfer), but the paper we're using (even the 3 year life one that we currently have) is long life thermal. The new stuff we're looking at is archival quality. Think airline tickets.
I'm open to suggestions on what else the software should have.
Can this be powered from a USB port (i.e., made to be portable), or will it require power from an outlet?
Due to the power requirements of the printer, it can't be powered from a standard USB port (500mA) although it may work from a high power 1Amp USB port.
Also, I'ld like the ability to print two (or more) copies.
This is a great idea, Thank you! I will try to make it so that when you press the button multiple times in succession it will queue up multiple copies to print.
Additionally I'ld also like to see a time and date on the printout, or maybe just some type of sequential number (so I could easily navigate through a stack of these to pull a specific one.)
That's a great idea, but the Linux computer that powers the device does not have a battery to keep track of the time across reboots. I think this may be a good feature for the GUI though, where it will force the user to set the time and date if they want a timestamp on the paper wallet.
I will definitely try to add the sequential number as well, thanks for the tip!