While Ben Franklin is known for printing Poor Richard's Almanac, he also printed some colonial currency such as this 20 Shilling note from the Colony of Delaware in 1759. He printed these along with David Hall who eventually printed Continental Currency along with William Sellers.
To foil counterfeiters Franklin, who wrote about the need for currency as early as 1729, began the practice of putting mica flakes in paper and printing leafs on currency as an effort to foil counterfeiters. (Source: http://www.loc.gov/exhibits/treasures/franklin-printer.html) Since paper money was in it's infancy and not readily accepted, this and other measures were employed to hinder counterfeiters. One such measure included putting strands of blue fiber in the paper. A counterfeiter was generally sentenced to death by hanging if they were caught. The reverse of this note states To Counterfeit is D E A T H, as a means of deterring counterfeiting.
20 Shillings, The Colony Of Delaware (1759)
Image Contribution: Handini