Though many European countries lay claim to the introduction of paper currency, the forerunner of today's dollar bill dates back to the early Chinese. To spare merchants from carrying heavy sacks of gold and valuables, a Chinese emperor, 600 years B.C., came up with the idea of crediting them with the value of their assets on pieces of paper. Today, the folding money in your pocket has developed from an easily foregable slip of paper into the almost impossible-to-duplicate modern bank note. In the unceasing war against counterfeiters, design, engraving, intermingled colours, even the distinctive "crackle" of the paper itself, have been put there to foil the efforts of would-be bogus-money makers. Canada's most recent issue of bank notes is considered to be among the toughest to counterfeit of any in the world. Simplicity of design and "feel" of the new notes are two safeguards ... though others designed to protect against "phonies" are still kept secret. The bills are printed under strict security by two Ottawa firms (the British American and Canadian Bank Note Companies) on instructions of the Bank of Canada. The new designs are almost free of ornamentation. Old-style type-faces have been exchanged for simpler characters. Using two-color offset lithography and printing from engraved steel plates, the new notes get their distinctive feel from being printed dry on special paper under heavy pressure. To duplicate them, the amateur money-maker would need large, expensive custom-built presses along with the skills of engravers, printers and lithographers. Though the bills, printed 24 to a sheet in bundles of 500 sheets, make an imposing sight, they're not legal tender until, as a final step (above) [photograph 73420], the Bank of Canada adds the signatures of its governors, J.E. Coyne and J.R. Beattie.