How to Identify Fake $100 Bills: Security Features of Real Currency

Security Features Checklist: Real vs Fake $100 Bills

Security Thread and UV Features

The security thread in genuine $100 bills is one of the most reliable features for distinguishing authentic currency from counterfeits. This thread is embedded vertically into the paper, positioned to the left of Benjamin Franklin's portrait, and runs from top to bottom of the note. The thread is imprinted with the letters USA and the numeral 100 in an alternating pattern, visible when you hold the bill up to light².

What makes this feature particularly difficult for counterfeiters to replicate is its behaviour under ultraviolet light. When you place a genuine $100 note under a UV lamp—commonly available at banks, retail counters, and currency verification stations—the security thread glows pink². Counterfeit notes typically fail this test in one of two ways: either the thread is printed on the surface rather than embedded in the paper, or it does not fluoresce at all under UV light.

To check the security thread yourself, hold the bill up to a bright light source. You should see a clear, continuous line running vertically through the note, not a printed stripe that sits on top of the paper. The alternating USA and 100 text should be legible and evenly spaced. If you have access to a UV light, the pink glow should be immediate and uniform along the entire length of the thread.

Counterfeiters often attempt to simulate the thread by printing a dark line on the note's surface, but this lacks the embedded quality and UV response of genuine currency. If the thread appears to be part of the printed design rather than woven into the paper itself, or if it does not glow pink under UV light, the bill is likely counterfeit. For broader context on identifying fake currency across denominations, see Understanding Fake Dollar Bills: Key Features.

3-D Security Ribbon

The 3-D Security Ribbon represents one of the most sophisticated anti-counterfeiting measures ever incorporated into U.S. currency. This ribbon is woven directly into the paper of the $100 note, positioned vertically to the right of Benjamin Franklin's portrait, and features images of bells and the numeral 100 that appear to move when you tilt the bill². Unlike printed security features, the ribbon is an integral part of the note's structure, making it exceptionally difficult for counterfeiters to replicate convincingly.

When you tilt a genuine $100 bill back and forth, the bells and 100s on the ribbon shift side to side; when you tilt the note up and down, the images move in the corresponding direction². This dynamic visual effect occurs because the ribbon is woven with thousands of micro-lenses that create the illusion of movement and depth. The images appear sharp and distinct, with smooth transitions as you change the viewing angle.

How to Test the 3-D Security Ribbon

Hold the bill at eye level and tilt it slowly from side to side. You should observe:

• Clear, crisp images of bells transforming into 100s as the angle changes
• Movement that corresponds directly to the direction you tilt the note
• A blue ribbon that appears to be embedded in the paper, not printed on the surface
• Consistent colour and clarity across the entire length of the ribbon

Counterfeit bills typically fail this test because the ribbon effect requires specialised manufacturing technology that is not accessible to most counterfeiters. Fake notes may display a printed blue stripe in the same location, but the images will remain static when tilted, or the "movement" will appear blurry and unconvincing. Some counterfeiters attempt to simulate the effect with holographic stickers, but these lack the woven quality and precise motion of genuine currency.

The 3-D Security Ribbon is particularly valuable for quick verification in retail and banking environments. You can check it without additional tools—just natural or indoor lighting and a simple tilt of the note. If the ribbon does not display clear, moving images, or if it appears to be a surface-level addition rather than woven into the paper, the bill is likely counterfeit.

Color-Shifting Ink

Genuine $100 bills incorporate color-shifting ink in two distinct locations, both designed to change from copper to green when you tilt the note at different angles. This optical security feature relies on specialised ink chemistry that counterfeiters find difficult to reproduce accurately, making it one of the most practical tests for verifying authenticity in everyday transactions.

The first color-shifting element appears on the front of the note, to the right of Benjamin Franklin's portrait: a bell housed within a copper inkwell. When you hold the bill flat and then tilt it away from you, the bell shifts from a copper tone to green². The transition should be smooth and immediate, with the colour change clearly visible under normal indoor or natural lighting. The bell itself is detailed and sharply defined, not blurry or pixelated.

The second color-shifting feature is the numeral 100 located in the lower right corner of the note's front side. This numeral also shifts from copper to green when you tilt the bill². Both elements—the bell in the inkwell and the numeral—should display the same copper-to-green transition, and the effect should be consistent across multiple viewing angles.

Testing Color-Shifting Ink

To verify these features yourself, hold the $100 note at eye level under adequate lighting. Tilt the bill slowly back and forth, observing both the bell in the inkwell and the numeral 100 in the lower right corner. You should see:

• A clear shift from copper to green as the angle changes
• Consistent colour transition in both locations
• Sharp, well-defined edges on the bell and numeral
• No residual copper or green tint when the bill is held flat again

Counterfeit notes often fail this test because replicating the optical properties of color-shifting ink requires advanced materials and manufacturing processes. Fake bills may display a bell and numeral printed in a single static colour—either copper or green—that does not change when tilted. In some cases, counterfeiters attempt to simulate the effect with metallic or holographic foil, but these materials produce a different visual result: either a rainbow shimmer or a metallic sheen that does not match the precise copper-to-green shift of genuine currency.

The color-shifting ink test is particularly useful because it requires no special equipment and works in a wide range of lighting conditions. If either the bell or the numeral 100 does not shift colour when tilted, or if the transition appears inconsistent or poorly defined, the bill is likely counterfeit. For additional guidance on identifying counterfeit currency across different denominations, see Understanding Fake Dollar Bills: Key Features.

Watermark and Paper Composition

Two of the most fundamental security features in genuine $100 bills—the watermark and the paper composition—are embedded directly into the note's structure during manufacturing, making them exceptionally difficult for counterfeiters to replicate. These features require no special equipment to verify and provide reliable indicators of authenticity in most verification scenarios.

The watermark in a genuine $100 note is a portrait of Benjamin Franklin, positioned to the right of the printed portrait on the front of the bill. When you hold the note up to a light source—such as a window, lamp, or overhead light—the watermark becomes visible from both sides of the note². The watermark portrait should appear as a faint but distinct image, with recognisable facial features and shading that matches the quality of the printed portrait. The image is created during the papermaking process, not added afterward, which means it is an integral part of the paper itself rather than a surface-level addition.

To test the watermark, hold the bill up to a bright light and look at the blank space to the right of Franklin's portrait. You should see a second, fainter image of Franklin that is visible from both the front and back of the note. The watermark should have clear outlines and tonal variation, not appear as a flat or blurry shadow. Counterfeit bills often fail this test in one of three ways: the watermark is absent entirely, it is printed on the surface of the paper (and therefore visible only from one side or without backlighting), or it appears as a poorly defined smudge rather than a recognisable portrait.

Paper Composition and Texture

The paper used to print genuine $100 notes is not ordinary paper. It is a specialised blend of 75 percent cotton and 25 percent linen, which gives authentic currency a distinctive texture and durability that counterfeiters struggle to replicate³. This composition produces a crisp, slightly rough feel when you touch the note, and a characteristic sound when you snap or crumple it. Regular paper—such as printer or copy paper—feels smoother and softer, and lacks the firmness and resilience of genuine currency.

When you handle a real $100 bill, you should notice:

• A firm, crisp texture that does not feel waxy or overly smooth
• A slight roughness to the surface, particularly where ink is raised
• A distinct sound when you hold the note taut and snap it between your fingers
• Durability that allows the note to withstand folding and handling without tearing easily

Counterfeit bills are typically printed on standard paper or low-quality cotton blends, which feel noticeably different from genuine currency. Fake notes may feel too smooth, too thin, or too stiff, and they often lack the subtle texture and sound of real bills. Some counterfeiters attempt to simulate the feel of genuine paper by coating their notes with wax or other substances, but this produces a slick, artificial texture that is easy to detect once you know what to look for.

The combination of the watermark and paper composition provides two complementary verification methods: one visual (the watermark visible under light) and one tactile (the texture and sound of the paper). If a bill fails either test—if the watermark is absent, poorly defined, or printed on the surface, or if the paper feels too smooth, too thin, or otherwise unlike genuine currency—the note is likely counterfeit. These features are particularly valuable for quick checks in retail and banking environments, where you may not have access to UV lights or magnifying tools but can rely on simple observation and touch.

Microprinting and Raised Printing

Genuine $100 bills incorporate two additional tactile and visual security features that counterfeiters find exceptionally difficult to reproduce: microprinting and raised printing. These features require different verification methods—one demands close visual inspection, whilst the other relies on touch—but both provide reliable indicators of authenticity when examined carefully.

Microprinting refers to text printed in extremely small type that appears as a solid line to the naked eye but resolves into legible words under magnification. On a genuine $100 note, microprinted text includes the phrase "THE UNITED STATES OF AMERICA" on Benjamin Franklin's jacket collar². This text is so small that most counterfeiters cannot replicate it accurately using standard printing equipment; fake bills typically display either a blurred line, a series of dots, or illegible characters in place of the microprinted phrase.

To verify microprinting, examine the left side of Franklin's portrait, focusing on the collar of his jacket. Under a magnifying glass or smartphone camera with zoom enabled, you should see clear, sharp letters spelling out "THE UNITED STATES OF AMERICA". The text should appear crisp and evenly spaced, without breaks or distortion. If the text is absent, blurry, or replaced by a solid line or random marks, the bill is likely counterfeit.

Raised Printing and Tactile Verification

Raised printing is a security feature you can verify by touch alone. Genuine $100 bills are printed using intaglio printing, a process that deposits ink in raised layers on the paper's surface. This creates a tactile texture on specific areas of the note, most noticeably on Benjamin Franklin's shoulder². When you run your fingertip lightly over Franklin's shoulder on the front of the bill, you should feel a distinct ridge or texture where the ink is raised above the paper.

To test raised printing, hold the bill flat and gently run your finger across Franklin's shoulder and the surrounding areas of the portrait. You should detect:

• A noticeable texture or ridge on Franklin's shoulder and clothing
• Raised ink on other printed elements, such as the Federal Reserve seal and serial numbers
• A consistent tactile quality across multiple areas of raised printing

Counterfeit bills are typically produced using offset or digital printing methods, which deposit ink in a flat layer on the paper's surface. Fake notes may look visually similar to genuine currency, but they lack the raised texture of intaglio printing. If the bill feels uniformly smooth, or if you cannot detect any raised areas when you touch Franklin's shoulder, the note is likely counterfeit.

Both microprinting and raised printing serve as complementary verification methods: microprinting tests the precision of the printing process, whilst raised printing tests the manufacturing technique. Together, they provide two independent checks that counterfeiters must overcome, and most fail at least one. For broader guidance on identifying counterfeit currency across different denominations, see Understanding Fake Dollar Bills: Key Features.

Complete Security Features Overview

The U.S. Department of the Treasury introduced the current design of the $100 note specifically to incorporate advanced security features that make counterfeiting significantly more difficult⁴. These features work together as a layered defence system: each element provides an independent verification method, and counterfeiters must replicate all of them convincingly to produce a passable fake. Understanding how these features function—and how they complement one another—allows you to verify authenticity quickly and reliably, whether you are handling a single bill or processing multiple transactions.

The four primary security features in a genuine $100 note are the security thread, the watermark, the 3-D Security Ribbon, and color-shifting ink¹. Each feature relies on a different verification method, which means you can check multiple indicators without specialised equipment. The security thread glows pink under ultraviolet light and contains imprinted text visible without magnification. The watermark—a portrait of Benjamin Franklin—becomes visible when you hold the note up to a light source, and it appears from both sides of the bill. The 3-D Security Ribbon is woven directly into the paper and displays bells and numerals that shift position when you tilt the note. Color-shifting ink changes from copper to green when the bill is tilted, affecting both the bell in the copper inkwell and the numeral 100 in the lower right corner.

Why does this layered approach matter? Counterfeiters typically focus on replicating the most visible features—such as portraits, serial numbers, and general layout—whilst neglecting the security elements that require advanced materials or manufacturing techniques. A fake bill may look convincing at first glance, but it will fail multiple verification tests when you examine the security thread, watermark, 3-D Security Ribbon, or color-shifting ink. By checking several features in sequence, you reduce the likelihood of accepting a counterfeit note that passes one test but fails others.

When you verify a $100 bill, start with the features that require no equipment: tilt the note to observe the 3-D Security Ribbon and color-shifting ink, hold it up to a light to check the watermark, and feel for raised printing on Franklin's shoulder. If all these features are present and function as described, the bill is almost certainly genuine. If any feature is absent, poorly defined, or behaves differently from documented behaviour, treat the bill as suspect and verify it further using a UV light or magnifying glass. For additional guidance on identifying counterfeit currency across different denominations, see Understanding Fake Dollar Bills: Key Features.

Common Mistakes and Misconceptions

When verifying the authenticity of $100 bills, individuals often fall prey to common mistakes and misconceptions that can lead to accepting counterfeit currency. We outline key pitfalls to avoid.

Relying Solely on Visual Inspection

Many people verify $100 bills by visual inspection alone, checking for obvious signs of counterfeiting such as blurry or distorted images. However, sophisticated counterfeiters can replicate visual elements convincingly. To avoid this pitfall, combine visual checks with tactile verification methods, such as feeling for raised printing on Benjamin Franklin's shoulder².

Ignoring the Security Thread

Some individuals overlook the security thread embedded in genuine $100 bills, which glows pink under ultraviolet (UV) light and contains imprinted text visible without magnification. Counterfeiters often fail to replicate this feature accurately. To verify the security thread, hold the bill under UV light and check for the pink glow and imprinted text².

Failing to Check for Microprinting

Microprinted text, such as "THE UNITED STATES OF AMERICA" on Benjamin Franklin's jacket collar, is a security feature that counterfeiters struggle to replicate. To verify microprinting, examine the left side of Franklin's portrait under magnification, looking for clear, sharp letters².

Misunderstanding the Legal Implications of Handling Counterfeit Currency

Unintentionally accepting or handling counterfeit currency can have serious legal consequences. If you suspect a $100 bill is counterfeit, do not attempt to pass it or return it to the person who gave it to you. Instead, follow the proper procedures for reporting suspected counterfeit currency to the authorities.

Overlooking the Importance of Paper Composition

Genuine $100 bills are printed on a specialised blend of 75% cotton and 25% linen, giving them a distinctive texture and durability. Counterfeit bills often lack this unique paper composition. To verify the paper composition, check the bill's texture and sound when handled, looking for a crisp, slightly rough feel and a characteristic sound when snapped or crumpled³.

Key Takeaways

To verify the authenticity of $100 bills, remember to:

• Check the security thread for a pink glow under UV light and imprinted text²
• Verify the watermark by holding the bill up to light to see Benjamin Franklin's portrait from both sides
• Examine the 3-D Security Ribbon for bells and 100s that move when tilted
• Feel for raised printing on Franklin's shoulder and other areas
• Use magnification to check microprinted text on Franklin's jacket collar

For further guidance on identifying counterfeit currency across different denominations, see Understanding Fake Dollar Bills: Key Features.

Evidence and sources

1. Training Course - Exam | U.S. Currency Education Program
2. $100 Note
3. Decoding Dollars $100 | U.S. Currency Education Program
4. U.S. Government Unveils New Design for the $100 Note | U.S. Department of the Treasury