Paper currency had its beginnings when individuals used to bring gold coins to the bank and exchange them for a receipt from the bank, which promised to repay them for their gold coins. The ease of use and tremendous portability of these receipts are what have made paper currency the norm around the world today. Today’s banknotes are printed in a wide variety of values and incorporate more security features than ever before. Here is a brief look at how paper currency is printed today—all in a streamlined process that involves heavy machinery to get the job done quickly and efficiently.
First, the paper (or paper blend) for the banknotes must be made and cut. The paper originates as a pulp that is shredded into fine pieces using a paper shredder. The paper material is then de-fibered as needed, and dust and foreign matter are removed from the material. Then, the paper material is ground in a large mashing machine that presses the fibers together. This mashing motion causes the fibers to closely intertwine, which gives the paper its strength. This paper material is then mixed with other chemicals to give the paper its final composition, and then the material passes through a paper making machine. This machine pours the paper material over a net to create a thin layer of paper, which is then dried and rolled up into a large roll of paper. This is the stage when delicate watermarks are laid into the paper as well. This large roll of paper then passes through a cutting machine that cuts the paper into precisely sized sheets.
Once the sheets have been cut, they are ready for printing. Using US currency as an example, the paper must pass through three different printing processes before they are ready for final cutting. First, the sheets are printed on an offset lithographic KBA Simultan press, which prints both the obverse and reverse sides of the banknote simultaneously. This particular press is capable of printing up to eight colors on each side. Once the sheets have dried for 72 hours after the first printing, they go through the intaglio process, which involves using large presses to leave relief-style embossing on the surfaces of the banknotes. Finally, the large sheets of banknotes are trimmed and pass through a letterpress machine, which applies serial numbers and seals to the banknote’s surface.
At this point, the banknotes are ready to be cut into single notes and distributed as legal currency.