I believe this is a Swiss franc note, but I am not sure. He has done many of the current euro bills, swiss francs, some older European currencies from before the introduction of the Euro and others. His art is very mathematically grounded and intricate. In his notebooks you could see complicated mathematical formulas used to generate some of the patterns and weaves found on bills. It was fascinating to be able to look at what would normally be a few inches square blown up on foam-core poster board.