It is the US dollar.

Related introduction:

The U.S. dollar is the legal tender of the United States of America. The U.S. dollar banknotes currently in circulation are those issued since 1929.

Appeared after the passage of the United States Coinage Act of 1792. The current issuance of U.S. dollars is controlled by the U.S. Federal Reserve System. Since 1913, the United States has established the Federal Reserve System and issued Federal Reserve Notes. More than 99% of banknotes currently in circulation are Federal Reserve notes.

Extended information

The main image on the front of the US dollar banknote is a portrait, and the main color is black. The main scene pattern on the back is a building, and the main color is green, but there are few differences in the colors of different versions. For example, the back of the 1934 version is dark green, the back of the 1950 version is grass green, and the back of the 1963 version is all dark green. The signature above is that of the Minister of Finance, and different Ministers of Finance were responsible for different issuance years.

U.S. dollar banknotes are made from cotton fibers and hemp. The long cotton fibers make the paper less likely to break, absorb ink well, and resist color fading. The hemp fiber is strong and tough, making the paper stiff, durable and lint-free, and has certain resistance to water, oil and some chemicals. There is no whitening agent added to the U.S. dollar paper, it is white and does not reflect light under a purple light.

Since 1880, U.S. dollar bills have been filled with red and blue fibers, which were mixed with pulp during papermaking. Therefore, some fiber threads are sandwiched in the paper, and some are floating on the surface. The fiber threads can be picked out with the tip of a needle.

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