All U.S. currency is produced by the Bureau of Engraving and Printing, which also designs, engraves, and prints items such as postage stamps. The box below describes how currency is printed. Since 1862 all U.S. currency had 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. Security Features Because U.S. currency is universally accepted and trusted, it is widely counterfeited. The U.S. Secret Service was created in 1865 to curtail counterfeiting. (See tips for spotting counterfeit 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¡ªthe portrait, vignette, ornaments, lettering, script, and scrollwork¡ªis 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 traditionally had a number of features that deter counterfeiters. One is the cotton and linen rag paper, which 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. Inks manufactured according to secret formulas by the Bureau of Engraving and Printing also help prevent counterfeiting. As advances in technology have made digital counterfeiting easier, more advanced security features have been added to deter counterfeiting. Two advanced features¡ªa security thread and microprinting¡ªwere first added in series 1990 notes, and several additional ones were incorporated into 1996 series notes. Most of these features were retained and others were added to the series 2004 redesign, which debuted in October 2003 with the $20 note. The redesigned $50 note was introduced in 2004 and the redesigned $10 note in early 2006. A redesigned $5 note will be issued in early 2008, with the $100 note to follow. No redesign is planned for the $2 and $1 notes. To stay ahead of counterfeiters, the Treasury plans to introduce new designs every seven to ten years. Redesigned and existing notes will circulate at the same time, with the new notes replacing the older ones as they wear out. Of course, all U.S. money, whether old or new, retains its full value because the United States never recalls any of its currency. The security features added to notes in the 1990s and in the 2004 redesign were recommended by an extensive study of counterfeit deterrence methods. The features in the 2004 redesign are illustrated in the diagram and described below. Color The most noticeable change in the 2004 series notes is the addition of subtle background colors, which differ for each denomination. On the $20 note, the background colors are green, peach, and blue. ¡°TWENTY USA¡± is printed in blue in the background to the right of the portrait. On the back of the note, small yellow numeral 20s are printed in the background. Although consumers shouldn¡¯t use color to check notes¡¯ authenticity, the use of more colors makes the notes more complex and more difficult to counterfeit. Portrait Another noticeable change is a larger portrait from which the border and surrounding fine lines have been removed. The portrait has been moved up and the shoulders have been extended into the borders. The portrait is off-center to reduce wear on the portrait and to provide more room for the watermark and security thread. Watermark A watermark, created during the paper-making process, depicts the same historical figure as the portrait. It is visible from both sides when held up to a light. Security thread An embedded polymer strip, positioned in a unique spot for each denomination, guards against counterfeiting. The thread itself, visible when held up to a bright light, contains microprinting¡ªthe letters USA, the denomination of the bill, and a flag. When viewed under ultraviolet light, the thread glows a distinctive color for each denomination. Color-shifting ink The ink used in the numeral in the lower right-hand corner on the front of the bill looks copper when viewed straight on but green when viewed at an angle. Microprinting Microprinting, which can be read only with a magnifier and becomes blurred when copied, appears in unique places on each denomination. On the $20 bill, it appears around the borders of the first three letters of the ¡°TWENTY USA¡± ribbon to the right of the portrait and in the border below the Treasurer¡¯s signature. Low-vision feature A large dark numeral in the lower right corner on the back of the note makes it easier for people with low vision to identify the note¡¯s denomination. Federal Reserve indicators A seal to the left of the portrait represents the Federal Reserve System. A letter and number below the left serial number identifies the issuing Federal Reserve Bank. Symbols of freedom The 2004 series features American symbols that will differ for each denomination. On the $20 note, a large blue eagle appears in the background to the left of the portrait. A smaller eagle printed in green metallic ink appears to the lower right of the portrait. Other Design Features Several other design characteristics of U.S. notes, some of which are shown in the diagram, are described below. click here to view Series The series identification shows the year the note design was first used. If a slight change is made in the note that does not require a completely new engraving plate¡ªfor example, a change in signature when the Secretary of the Treasury or the Treasurer of the United States changes¡ªthe year remains the same and a letter is added to show that the design differs slightly from previous printings. A C suffix, for example, as in ¡°Series 1935C,¡± means that the original design has been changed slightly three times. Serial number Beginning with the 1996 series, serial numbers consist of two prefix letters (except on $1 and $2 notes, which have one prefix letter), eight numerals, and a one-letter suffix. The serial number appears twice on the front of the note. No two notes of the same kind, denomination, and series have the same serial number. This fact can be important in detecting counterfeit notes; many counterfeiters make large batches of a particular note with the same number. 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. Size 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. Portraits and emblems The seven denominations of notes now produced by the Bureau of Engraving and Printing feature portraits of American statesmen on the face and emblems and monuments on the back. Bank tellers and others who frequently handle currency use the portrait in assembling and counting it. They assemble each denomination separately and uniformly¡ªface 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. "In God We Trust" Secretary of the Treasury Salmon P. Chase first authorized use of "In God We Trust" on U.S. money¡ªon the two-cent coin in 1864¡ªafter receiving a number of appeals from citizens urging that the Deity be recognized on U.S. coins. In 1955, Congress mandated the use of this phrase on all currency and coins. All denominations of paper money now being issued carry the motto.