OP: Why couldnāt traditional Chinese Yinpiaoé¶ē„Ø/silver drafts be forged if they were merely slips of paper? (cr大ęå®éļ¼ęøč¶)
Traditional Chinese yinpiao/silver drafts were paper vouchers issued by private banks starting from the Song Dynasty(960ā1279). People could exchange these slips for physical silver at bank branches across the country.
Silver drafts were made in multiple copies with matching serrated seal edges. One copy went to the customer and others stayed at the bank. All edges had to fit perfectly together to withdraw silver. The unique split edge marks were almost impossible to copy.
This mechanism is known as qifengéŖē¼ (split-joint seal) in China. It first originated in the Western Zhou Dynasty (1046ā771 BC). The Rites of Zhou records that contracts were written on bamboo or wooden slips in duplicate. Notches and marks were carved in the middle before splitting the slips, with each party keeping one half. The two halves would be matched by their notches for verification.
During the Spring and Autumn and Warring States periods (770ā221 BC), this idea evolved into hufuč符/tiger tally tokens. A military tally was split into two pieces with identical inscriptions carved along the split edge. Troops could only be deployed if the patterns and characters on both halves perfectly aligned, serving as a metal version of the split-joint anti-counterfeiting system.
The technology matured in the Tang Dynasty (618ā907). Government documents and private contracts commonly used split-joint seals stamped across the dividing line. The Chinese character "hetongåå" (contract) was written across the middle before the paper was torn apart, so the complete characters would only appear when the two halves were put together. This split-coupon system was later adopted for Song Dynasty (960ā1279) jiaozi paper money and yinpiao/silver drafts of the Ming and Qing dynasties (1368ā1912).
Official Song dynasty paper money (Jiaoziäŗ¤å) was abolished in 1107. Private silver drafts issued by Qing-era piaohaoē„Øč” (ancient exchange banks) vanished completely in 1951, hit hard by modern banks and currency reforms. Nowadays silver drafts no longer circulate as currency. Their collectible value depends on their rarity and physical condition.
Split-joint seals (éŖē¼ē« qifengzhang)are still widely used on important paper documents in modern China, an anti-tampering technique passed down from ancient times. They are applied across the edge of multi-page contracts, bidding documents and official archives. If any page is removed or replaced, the broken seal pattern can prove the file has been altered.
OMG I got so excited about this because they used a really similar (though far less refined) version of this for contracts in the European medieval period!
First they were called "chirographs", but later the word "indenture" (in its earliest meaning as just a legal document of any kind between two people) came to be used, originating from the practice of a contract being written twice on a single piece of parchment and then cut in half with serrated edges (as in dent, "teeth" -> indents -> indenture) in order for each party to take one half, so they could later piece them together and verify that there had been no forgery -- same as the Chinese silver drafts!
(Charter of the ClerecĆa de Ledesma, 1252, showing the serrated indents at the top -- presumably they are cutting rather than tearing because they're using parchment, which I expect is much harder to tear than wood-pulp paper like the Chinese were using)
Delights me when human beings find similar ways to solve the same problem at two different ends of the world. <3
This was also used for Taxes in England - A hazel stick was used. It was notched to show the amount of taxes then split. The two splits had to match up perfectly to prove tax had been paid.
Remarkably, this ran from the 12th century to 1826.
Famously, there were so many tax record sticks that they were burned for fuel in a practical but slightly upsetting display of historical record autodestruction.
That said, apparently, while they were being burned in 1836, the fire overheated the furnace and set fire to the Palace of Westminster: The one that's there today is the New One.
I'm sure upon hearing that the Tax offices burned themselves down, the citizens of Albion commented "shame," and went back to eating cheese.



















