Depending on what you want, Mark, you can start by buying some HP Advanced photo paper that is thicker than printer paper but will still load and cycle through an inkjet printer -- at least it does on my HP 8620. I've done a few labels that way and then cut to size and glued them into the gun case.

Plan B, and I have not yet tried it, would be to glue thin leather onto the appropriate size of printer paper and see if it will cycle through your printer.

Regards, Tim