Paper money seal (China)

The economy of China during the Song dynasty outpaced the supply of traditional coinage, leading the government to issue paper money (Jiaozi (交子)) to increase the money supply.

The cash seal was developed as an anti-counterfeiting measure; official government notes received a red, sometimes black or purple, stamp at their centres.

This forced counterfeiters to attempt to replicate the seal, presumably leading to distinguishable lower quality stamps.

[citation needed] The Ming government department responsible for cash affairs and the use of the cash seal was the Baochao Bureau (simplified Chinese: 宝钞局; traditional Chinese: 寳鈔局; pinyin: Baochao Ju).

In Japan, ginkō-in (Japanese: 銀行印) seals have similar functions.

A Yuan dynasty government note and its matrix. The Mongolian dynasty used 'Phags-pa script , Tibetan originated writing, beside hanzi at this time.
A Ming dynasty government note with two seal stamps in the centre.
Qing dynasty notes. In the centre of the left note is the Seal of Cash of the Great Qing (大清宝钞之印).