english £5 notes. The Bank of England had them printed to be given to diplomats upon the handing over of Hong Kong to China. They were never given out and the Bank sold them at face.
I folded one sheet of 20 down to the size of one note and took it to the Barracuda Club from time to time. I would throw it down on the roulette table and say 'new color please' when there was a novice dealer there. The dealer would never know what to do. The suits would be in hysterics.