still in the testing stages, but just to let others know that are going to be using a blank tin like me (hense tinty pi, and not minty pi)
i tried a few methods, but the one that i'm going to go with is the vinyl gloss sticker paper route
http://www.ebay.co.uk/itm/162311025607
its waterproof and has a nice feel to it, and more importantly the results are very good (especially coming from my basic inkjet printer at home)
first attempt (slightly rushed) and without the use of any heat (hairdryer or similar) to make it go around the corners easier
and my knife work needs a little more attention....
but it sticks and applys really easily (room for correction if you go wrong, as vinyl should be)
not the finished product, and i may end up giving the final tin a coat or two of clear lacquer (to add more durabilty, not sure if it will be matt or gloss)