Since 1862 all U.S. currency has been printed in Washington, D.C., but to help meet increasing demand, a second printing facility was opened in Fort Worth, Texas, in 1991. Fort Worth now produces about half the nation's currency.
U.S. currency is printed by the engraved intaglio steel plate method, a complicated procedure that gives notes an embossed feel and other distinctive features difficult to counterfeit.
For security reasons each feature of a note—the portrait, vignette, ornaments, lettering, script, and scrollwork—is the work of a separate, specially trained engraver. A geometric lathe is used to produce the intricate lacy design and borders.
A steel die is made of each feature. Rolls made from these dies are put together into a master die of the complete note. The master die is then used in the first of a series of operations leading to the making of press plates from which the notes are printed.
U.S. currency has many features that deter counterfeiters. One is the cotton and linen rag paper it is printed on. The paper has a distinctive, pliable feel and has tiny red and blue fibers embedded in it. Though a commercial company produces the paper, it is illegal for anyone to manufacture or use a similar type except by special authority. Special inks manufactured by the Bureau of Engraving and Printing according to secret formulas also help prevent counterfeiting.
As technology advances and copiers, printers, electronic digital scanners, color work stations, and computers become more sophisticated, more advanced security features have been added to deter counterfeiting. Two of these advanced features—a security thread and microprinting—were first added in series 1990 notes. These two features and a number of additional ones were incorporated into a series of completely redesigned notes that first appeared in 1996 with the $100 note. The redesigned $50 and $20 notes appeared in 1997 and 1998, respectively. Most, if not all, of these features will appear in the redesigned lower-denomination notes.
Redesigned and existing notes will circulate at the same time. As older notes wear out and as the new-design currency is available, the new notes will replace the older ones. Of course, all U.S. money, whether old or new, retains its full value as the United States has never recalled any of its currency.
In determining what features would be most effective in deterring counterfeiting of U.S. currency, more than 120 security features were examined and tested, including some used in other nations' currencies. The features chosen are illustrated in the diagram and described below.
Notes are numbered in lots of 100 million. Each lot has a different suffix letter, beginning with A and following in alphabetical order through Z, omitting O because of its similarity to the numeral zero.
Because serial numbers are limited to eight numerals, a "star" note is substituted for the 100 millionth note. Star notes also replace notes damaged in the printing process. Made up with independent runs of serial numbers, star notes are exactly like the notes they replace except that a star is substituted for one of the serial letters.
Serial numbers on the redesigned, series 1996 currency differ slightly from those of previous series. The new serial numbers consist of two prefix letters, eight numerals, and a one-letter suffix. The first letter of the prefix designates the series. The second letter of the prefix designates the Federal Reserve Bank to which the note was issued.
Bank tellers and others who know how to handle currency use the portrait in assembling and counting it. They assemble each denomination separately and uniformly—face up and top up. This practice also helps handlers detect counterfeit and altered notes. All Reserve Banks require banks to arrange their currency for deposit in this way.