The security features found in United States currency are selected after extensive testing and evaluation of hundreds of bank note security devices, many of which are used successfully by other countries with lower production and circulation demands. Learn more about the Series 2004 and 2006 security features in the New Money section of our website.

Security Features Introduced in Series 1996 Notes:

Watermark: The watermark is formed by varying paper density in a small area during the papermaking process. The image is visible as darker and lighter areas when held up to the light. Since the watermark does not copy on color copiers or scanners, it makes it harder to use lower denomination paper to print counterfeit notes in higher denominations and is a good way to authenticate the note. It depicts the same historical figure as the engraved portrait.

Color-Shifting Inks: These inks, used in the numeral on the lower right corner of the face of the note, change color when the note is viewed from different angles. The ink appears green when viewed directly and changes to black when the note is tilted.

Fine-Line Printing Patterns: This type of line structure appears normal to the human eye but is difficult for current copying and scanning equipment to resolve properly. The lines are found behind the portrait on the front and around the historic building on the back.

Enlarged Off-Center Portraits: The larger portrait can incorporate more detail, making it easier to recognize and more difficult to counterfeit. It also provides an easy way for the public to distinguish the new design from the old. The portrait is shifted off center to provide room for a watermark and unique "lanes" for the security thread in each denomination. The slight relocation also reduces wear on most of the portrait by removing it from the center, which is frequently folded. The increased image size can help people with visual impairments identify the note.

Low-Vision Feature: A large dark numeral on a light background on the lower right corner of the back. This numeral, which represents the denomination, helps people with low vision, senior citizens and others as well because it is easier to read. This feature first appeared on the Series 1996 $20 note.

Also, a machine-readable feature has been incorporated for the blind. It will facilitate development of convenient scanning devices that could identify the denomination of the note.

Pre-1996 Series Security Features:

Security Thread: A security thread is a thin thread or ribbon running through a bank note substrate. All 1990 series and later notes, except the $1 and $2 notes, include this feature. The note's denomination is printed on the thread. In addition, the threads of the new $5, $10, $20 and $50 notes have graphics in addition to the printed denomination. The denomination number appears in the star field of the flag printed on the thread. The thread in the new notes glows when held under a long-wave ultraviolet light. In the new $5 note it glows blue, in the new $10 note it glows orange, in the new $20 note it glows green, in the new $50 note it glows yellow, and in the new $100 note it glows red. Since it is visible in transmitted light, but not in reflected light, the thread is difficult to copy with a color copier which uses reflected light to generate an image. Using a unique thread position for each denomination guards against certain counterfeit techniques, such as bleaching ink off a lower denomination and using the paper to "reprint" the note as a higher value note.

Microprinting: This print appears as a thin line to the naked eye, but the lettering easily can be read using a low-power magnifier. The resolution of most current copiers is not sufficient to copy such fine print. On the newly designed $5 note, microprinting can be found in the side borders and along the lower edge of the portrait's frame on the face of the note. On the new $10 note, microprinting appears in the numeral "10" in the lower left-hand corner and along the lower edge of the portrait's frame on the face of the note. On the Series 1996 $20 notes, microprinting appears in the lower left corner numeral and along the lower edge ornamentation of the oval framing the portrait. On the $50 notes, microprinting appears on the side borders and in Ulysses Grant's collar. On the $100 notes, microprinting appears in the lower left corner numeral and on Benjamin Franklin's coat. In 1990, 1993 and 1995 series notes, "The United States of America" is printed repeatedly in a line outside the portrait frame.

In December 1993, the National Research Council (NRC), funded by the Department of the Treasury, published Counterfeit Deterrent Features for the Next Generation Currency Design. This report analyzed and recommended overt counterfeit deterrent features that could be incorporated into a redesign of U.S. banknotes. The developmental costs for the 1996 Series currency notes were $265,376 to fund the NRC study, and approximately $500,000 to purchase test quantities of features and carry out internal BEP analyses.

Security Feature Evaluation Criteria:

Effectiveness: Counterfeit deterrent effectiveness was tested by reprographic equipment manufacturers and government scientists. They also considered the ease of public and cash handler recognition.

Durability: Durability was tested rigorously. Tests included crumpling, folding, laundering, soiling and soaking in a variety of solvents such as gasoline, acids and laundry products.

Production Costs: Research and production expenses will increase the cost of each note by about two cents. The Federal Reserve System has funded the development and introduction of the new currency through earnings the Federal Reserve receives primarily from interest on its holdings of U.S. government securities.

Appearance: The currency still has a familiar American look. The size of the notes, basic colors, historical figures and national symbols are not changing. New features were evaluated for their compatibility with the traditional design of United States currency.