Exactly speaking, the raw materials are not only paper, but also gold foil, silver foil, bark, leaf, leather, cloth or fur.

没错来说，不仅是原材料纸张，而且金箔，银箔，树皮，叶，皮，布或毛皮。

youdao

All of them produced large amounts of paper money -- many times the amount they could exchange for gold or silver.

VOA: special.2009.01.01

The Treasury Department would buy the silver with new paper money that could be exchanged for silver or gold.

VOA: special.2010.06.17

The government would pay for the silver with paper money -- treasury notes -- which could be exchanged for gold or silver money.

VOA: special.2010.06.03

Coinage fluctuated between all gold (less frequently) or all silver (more frequently) or all paper or all Spanish for the dollar.

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There was no paper, copper, or silver just thirty-one thousand lines of code and an announcement on the Internet.

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Paper currency began as warehouse receipts for specified weights of gold or silver.

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