Ancient Chinese Paper Money Had Warnings Against Counterfeiting

Before the invention of paper currency, conducting large-scale commerce in Song Dynasty China involved lugging around thousands of heavy metal coins strung together. To solve this problem, merchants began using privately issued notes of deposit known as "jiaozi." The government soon recognized their potential and, around 1000 CE, began issuing the world's first state-backed paper money. To protect the integrity of this revolutionary system, authorities embedded sophisticated security features directly into the notes, a practice that continues with modern currency today.

These early bills were far from simple slips of paper. They were printed on special paper made from mulberry bark, often mixed with other fibers to create a unique texture that was difficult to replicate. The notes featured intricate, multi-colored designs and were stamped with a series of complex official seals in red and black ink. Most strikingly, they carried a stark warning promising decapitation for anyone daring to produce a forgery. Despite these extreme measures, the immense potential profit meant that counterfeiting was a constant battle, forcing the government to periodically change designs and recall old notes throughout history.