There is a frequently reinvented idea used in divining the serial number on a dollar bill, wherein known bills are switched in for borrowed ones. To enable the performer to identify the chosen one, the switched-in bills are folded in different ways, so that one shows primarily green, one shows primarily black, and one primarily white. This can be found under the title of “Marvelous Bank Note Test” in Joseph Ovette's Bargain Magic, 1921, p. 20.