US founding father Benjamin Franklin is best known today as the inventor of the lightning rod and for his role in US independence. But the trained printer also devised new methods to make banknotes counterfeit-proof, as a study has now shown. The colonial banknotes produced by Franklin’s printers went a long way toward making the American colonies financially independent of Britain even before the US was founded.
Benjamin Franklin played a key role in the independence efforts of the English colonies in North America and was also instrumental in formulating the US Constitution in 1776. He is therefore considered one of the founding fathers of the USA. But Franklin made another little-known contribution to American independence several decades earlier. By 1730, Franklin owned a printing and publishing house in Philadelphia, but already had extensive insight into transatlantic politics and economics.
Paper money for the American colonies
“Benjamin Franklin realized that for the colonies to be politically independent, they also had to become financially independent,” explains Khachatur Manukyan of the University of Notre Dame in Indiana. At that time, the American colonies depended on silver and gold coins coming in by ship from Britain. However, these were largely used to pay for imported goods. “As a result, there was not enough money left for the young colonies to strengthen and expand their own economies,” says Manukyan.
Therefore, people began to experiment with the first printed banknotes, which, however, were not yet standardized and easy to counterfeit. Therefore, in this situation, Franklin used his papermaking and printing experience to develop banknotes that were less easy to counterfeit. In the course of his career, a whole network of paper mills and printers developed that supplied the young colonies with paper money. In all, more than 2.5 million notes of Franklin’s paper money were put into circulation in Delaware, New Jersey, and Pennsylvania alone.
Anti-counterfeiting by several methods
Manukyan and his colleagues have now investigated the methods Franklin used to protect his banknotes from counterfeiting. To do this, they analyzed and compared around 600 banknotes that were printed in North America between 1709 and 1790, including some from Franklin’s production, but also previous versions and counterfeits. It turned out that the Franklin banknotes were printed on a special paper to which blue microfibers had been added to give it a texture that was difficult to replicate. In addition, imprints of plant leaves on the back of the paper should make counterfeiting more difficult.
Another feature of the banknote paper was tiny, translucent crystals of the layered silicate mineral muscovite. This forms fine flakes that shimmer slightly and are semi-transparent. In the banknotes, they made the paper more durable and resilient, while the subtle shimmer of the crystals served as another hallmark of genuine banknotes. But Franklin also came up with new ideas for the printer ink for his banknotes: “Our results suggest that Franklin developed a unique, graphite-based black ink variant for banknote printing,” report Manukyan and his colleagues. The black inks that were common at the time, on the other hand, were made from bone ash or lampblack.
According to the scientists, this proves that Benjamin Franklin pioneered the development of counterfeit-proof banknotes. He devised several methods to protect the official paper money of the American colonies from imitations. “These features and inventions made the paper money of that time an archetype for the development of banknotes – for centuries,” states the research team.
Source: University of Notre Dame; Specialist article: Proceedings of the National Academy of Sciences, doi: 10.1073/pnas.2301856120