Performer shows a knife and a currency bill or note which may be borrowed. A piece of paper, the same size as the bill is folded in half, and the knife pushed through the middle. When the knife is pulled sideways, it rips through the paper, as expected.
He then places the bill over another piece of paper of the same size and creases them in half. The knife is pushed through both the bill and paper. He opens the crease and the spectators can see the knife going right through the bill and paper from both sides. The performer creases them again, and pulls away the knife ripping through the bill and paper at the crease. When he opens them, the paper is found to be ripped as one would expect, but the bill is totally unharmed.
We supply the special mechanical paper knife (with wooden handle, and steel blade) that makes the illusion possible, along with complete performing instructions. You can perform this with any borrowed currency bill.