How to Print Paper Money Using Intaglio Currency Printing

In the print and printmaking world, intaglio printing one of the three basic types of printing. Intaglio printing differs from other printing types because lines and crevices form images made below the surface of the plate. These crevices are filled with ink and forced onto the substrate using great pressure. It is essentially the opposite of relief printing techniques. This printmaking technique involves the use of engraving or etching the image to be printed into a copper or steel plate using either a tool called a burin or graver. A combination of wax and acid make lines below the plate’s surface by eating away at the exposed metal surface. The end of the burin or graver tool is shaped like a wedge and allows the artist to make lines in the wax or metal at varying depths. Lines that are deeper hold more ink and when printed, produce a deeper tone. An etching needle is used to carve into an acid resistant wax layer that is spread across the metal. After the artist has completed the piece it is dipped into an acid bath where the acid eats away at the exposed metal to form the crevices that will hold the ink. When the plate is complete, it is covered with ink and then scraped leaving ink only in its crevices. Great pressure is then used to transfer the ink in the plate to the paper. This leaves the surface slightly raised and the backside slightly depressed.

Intaglio printing was developed during the 15th century in Germany. Copper was originally used to etch plates. Etching comes from the Latin word “radere,” meaning to scratch or to scrape. Copper is an ideal metal for this process but proved to be too soft after many impressions were made. This problem was solved in the late 1850’s in France by using a method called steel facing. This process put a “skin” of steel over a copper plate that was only a few thousandths of an inch thick. Etchers now could have the best of both worlds in their work; soft copper to etch into, and the long lasting steel surface allowed for more impressions.

The United States Government began printing money in 1862. The first currency that was issued called a “greenback” was created to finance the Civil War. There were five clerks that would affix the treasury seal to the bills using intaglio-printing techniques. Later the Government formed the Bureau of Engraving and Printing or BEP. According to the US Department of Treasury website their purpose was to design and manufacture US currency; design and manufacture postage stamps, customs stamps and revenue stamps design, engrave and print Treasury bills, notes and bonds, and other U.S. securities; design engrave and print commissions, permits, and certificates of awards. Until July 1929 U.S. currency was 7.42 inches by 3.13 inches. Currency printed since 1929 is 6.14 inches by 2.61 inches, a size easier to handle and less expensive to produce.

The printing of US currency is possibly the greatest challenge in the industry. US dollars are one of the most widely accepted forms of money in the world. However, this makes it a prime target for counterfeiting around the world. The Secret Service was created first to stop counterfeiting in 1865 and is still taken very seriously. The U.S. uses an engraved intaglio steel plate and complex procedures give notes an embossed feel. In order to make the bills produced more secure, a separate engraver creates each different feature of the bill. Then, geometric lathes are used to produce the elaborate design and border decorations. Steel dies are then produced of the individual features and rolls are made. Each individual design component is combined into a master plate that the press plate is finished from. The plates are specially designed to print on a substrate that is 75% cotton and 25% linen. Sometimes called “rag” paper because it has no wood fiber and is essentially not really paper. The 75/25 mix gives the bill its strength and resistance to moisture.