Really nice Post, I already had a look at a similar Post on the same topic that was written in German. But it didn t explain the technology that well. Well you still need a smartphone to check if there is really Bitcoin on the banknote. The upside is that passing arround that banknotes doesn t cost you any transaction fees untill you want to take the money away from the banknote. You also take away some traffic from the Bitcoin network by useing the banknotes. Do you have any information about the cost for producing the banknotes ?