Security Features Verification Checklist for $100 Bills
| Security Feature | How to Check | What to Look For | UV Light Test |
|---|---|---|---|
| Color-Shifting Bell | Tilt the note | Bell in copper inkwell shifts copper to green | Not applicable |
| Color-Shifting Numeral | Tilt the note | Numeral 100 (lower right) shifts copper to green | Not applicable |
| 3-D Security Ribbon | Tilt the note side to side | Bells and 100s move side to side or up and down | Not applicable |
| Watermark | Hold note to light | Benjamin Franklin visible from both sides | Not applicable |
| Security Thread | Hold note to light | Imprinted with USA and 100 in alternating pattern | Glows pink under UV light |
Key Security Features of a Real $100 Bill
What makes a genuine $100 note difficult to counterfeit? The U.S. Department of the Treasury has embedded multiple security features into the current design, each verifiable without specialised equipment1. These features work together: counterfeiters typically replicate one or two elements but struggle to reproduce all of them convincingly. When you check a $100 bill, you're looking for four primary features that respond to light, movement, and touch.
The security thread runs vertically through the note and is imprinted with the letters USA and the numeral 100 in an alternating pattern2. Hold the bill to light and you'll see this thread embedded in the paper—not printed on the surface. Under ultraviolet light, the thread glows pink2. Counterfeit notes often use a printed line or omit the thread entirely, because embedding material into paper during manufacture requires access to the Treasury's proprietary process.
The watermark of Benjamin Franklin appears when you hold the note to light2. This image is visible from both sides of the bill and matches the portrait printed on the front2. The watermark sits to the right of Franklin's main portrait and should look three-dimensional, not flat. If the watermark is missing, printed on the surface, or shows a different face, the note is counterfeit.
The 3-D Security Ribbon is woven into the paper on the front of the note2. Tilt the bill and watch the images of bells and 100s shift: they move side to side when you tilt the note horizontally, or up and down when you tilt it vertically2. This ribbon is blue and distinct from the security thread; it's positioned to the right of Franklin's portrait. Counterfeiters cannot replicate the depth and motion of this feature with printing alone.
Colour-shifting ink appears in two places. The bell inside the copper inkwell on the front of the note changes from copper to green when you tilt it1. The numeral 100 in the lower right corner of the front also shifts from copper to green with the same tilting motion2. Both elements should change colour smoothly and simultaneously; if the ink remains one colour or looks dull, the note may be fake.
Each feature serves a specific purpose: the thread and watermark confirm the paper's authenticity, the ribbon and colour-shifting ink verify the printing process, and the UV response provides a quick electronic check. Together, they create a layered defence that makes high-quality counterfeiting prohibitively difficult. For a broader overview of detecting counterfeit currency across denominations, see How to Identify Fake Dollar Bills: Detection Guide.
How to Check the Color-Shifting Ink on a $100 Bill
Color-shifting ink provides one of the quickest visual checks you can perform without equipment. The $100 note uses this ink in two locations on the front of the bill, and both elements should change colour in the same way when you tilt the note. Counterfeiters often print these features in static ink—copper or green—but cannot replicate the shift itself, because the ink formula and application process are controlled by the U.S. Department of the Treasury.
Start with the bell inside the copper inkwell, located to the right of Benjamin Franklin's portrait. Hold the note flat and observe the bell's colour: it should appear copper. Tilt the note slowly away from you or towards you, keeping it under consistent light. The bell will shift from copper to green as the angle changes3. The transition should be smooth and distinct, not a gradual fade or a patchy mix of colours. If the bell remains copper or green regardless of angle, or if the colour looks printed rather than metallic, the note is likely counterfeit.
Next, check the numeral 100 in the lower right corner of the front of the note. This numeral uses the same color-shifting ink and should behave identically to the bell. Tilt the note and watch the 100 shift from copper to green2. Both the bell and the numeral should change colour at the same tilt angle and with the same intensity. If one element shifts but the other does not, or if the colours differ between the two features, the note has been altered or printed with standard ink.
Perform this check in natural or bright artificial light; dim lighting can obscure the colour shift. Tilt the note at a 45-degree angle or more to see the full transition. The shift occurs because the ink contains microscopic flakes that reflect different wavelengths of light depending on the viewing angle—this optical effect cannot be photocopied or reproduced with conventional printing. When both the bell and the numeral shift smoothly from copper to green, you've confirmed one of the note's core security features.
How to Verify the Security Thread and Watermark
The security thread and watermark are embedded features that confirm the paper itself is genuine, not a printed imitation. Both are visible when you hold the note to light, and the thread provides an additional check under ultraviolet illumination. Counterfeiters struggle to replicate these elements because they require specialised paper manufacturing—printing a line or image onto the surface does not produce the same effect. When you verify these features, you're testing whether the bill was produced using the U.S. Department of the Treasury's controlled paper stock.
Checking the Security Thread
The security thread runs vertically through the note, embedded in the paper rather than printed on it. Hold the $100 bill up to a light source—natural daylight or a bright lamp works well—and look for a thin vertical strip to the left of Benjamin Franklin's portrait. This thread is imprinted with the letters USA and the numeral 100 in an alternating pattern2. The text should be clear and evenly spaced, not blurred or incomplete. If you cannot see the thread when holding the note to light, or if it appears to be a printed line on the surface, the note is counterfeit.
The thread also responds to ultraviolet light. Place the note under a UV lamp or blacklight: the security thread will glow pink2. This glow should be bright and uniform along the entire length of the thread. Counterfeit notes may use a thread that does not glow, glows a different colour, or shows uneven fluorescence. If you do not have access to a UV light, the visible thread check alone provides strong evidence of authenticity, but the UV test adds a quick electronic confirmation when available.
Checking the Watermark
The watermark of Benjamin Franklin is visible from both sides of the note when you hold it to light2. This image sits to the right of the printed portrait on the front of the bill and should match Franklin's face in detail and proportion. The watermark appears three-dimensional and embedded in the paper fibres, not flat or printed. Turn the note over and hold it to light again: the watermark should remain visible and identical from the reverse side2. If the watermark is missing, printed on the surface, or shows a different face, the note is fake.
The watermark's position and clarity matter. It should be sharp enough to distinguish facial features, and it should align with the main portrait without overlapping it. Counterfeiters sometimes print a faint image in the watermark area, but this will look two-dimensional and may smudge or blur under close inspection. A genuine watermark is part of the paper itself, created during manufacture by varying the paper's thickness, so it cannot be removed or altered without destroying the note.
Both the security thread and the watermark require holding the note to light at a consistent angle. Perform these checks in a well-lit area, and compare the results to a known genuine bill if possible. When both features are present and behave as described, you've confirmed two of the most difficult-to-counterfeit elements of the $100 note.
How to Examine the 3-D Security Ribbon
The 3-D Security Ribbon is one of the most advanced security features on the $100 note, and it's also one of the easiest to verify without equipment. This blue ribbon is woven directly into the paper on the front of the bill, positioned to the right of Benjamin Franklin's portrait. Unlike printed features, the ribbon contains images that shift and move when you tilt the note, creating a dynamic visual effect that counterfeiters cannot replicate with standard printing techniques. When you examine this ribbon, you're testing whether the bill was manufactured using the U.S. Department of the Treasury's proprietary paper and security processes.
Hold the $100 note flat in front of you, with the front facing up and Benjamin Franklin's portrait visible. Locate the blue vertical ribbon to the right of the portrait—it runs from top to bottom and is distinct from the security thread, which sits further to the left. The ribbon contains images of bells and the numeral 100, and these images appear to be embedded within the ribbon itself, not printed on the surface2.
Tilt the note slowly from side to side, keeping it under consistent light. As you change the angle, the images of bells and 100s will move side to side across the ribbon2. The motion should be smooth and continuous, with the images appearing to shift position as though they are sliding along the ribbon's length. Now tilt the note up and down, moving the top edge towards you and then away. The same images will move up and down in response to this vertical tilt2. This dual-axis movement—side to side and up and down—is the defining characteristic of the 3-D Security Ribbon and cannot be reproduced by photocopying or printing a static image.
The ribbon's colour and texture also matter. It should appear blue and slightly raised from the paper's surface, because it is woven into the note rather than printed. If the ribbon looks flat, printed, or does not show any movement when tilted, the note is counterfeit. Some counterfeiters print a static image of the ribbon, but this will not produce the shifting motion or the three-dimensional depth of a genuine ribbon. The images should remain sharp and distinct at all tilt angles; blurred or incomplete images suggest a fake.
Perform this check in natural or bright artificial light, and tilt the note at various angles to observe the full range of motion. The 3-D Security Ribbon works in tandem with the other features—colour-shifting ink, watermark, and security thread—to create a layered defence. When the ribbon's images move smoothly in both directions, you've confirmed one of the most difficult-to-counterfeit elements of the $100 bill.
Understanding the New $100 Note Design
The U.S. Department of the Treasury unveiled a redesigned $100 note specifically to combat counterfeiting with advanced security features that are difficult to replicate4. This design, which remains in circulation today, introduced several layered protections: a security thread, a watermark of Benjamin Franklin, a 3-D Security Ribbon, and colour-shifting ink1. Each feature serves a distinct purpose in the verification process, and together they create a system that requires counterfeiters to overcome multiple technical barriers simultaneously. When you check a $100 bill, you're testing whether it was produced using the Treasury's controlled paper stock, proprietary inks, and specialised manufacturing processes—elements that are not available to counterfeiters.
The redesign prioritised features that anyone can verify without equipment, alongside elements that respond to electronic checks. The security thread and watermark confirm the paper's authenticity, because they are embedded during manufacture rather than printed on the surface1. The 3-D Security Ribbon adds a dynamic visual element that shifts when tilted, creating motion that cannot be photocopied or printed with conventional techniques1. The colour-shifting ink appears in two locations—the bell in the copper inkwell and the numeral 100 in the lower right corner—and both shift from copper to green at the same tilt angle1. This combination of visible, tactile, and light-responsive features means you can perform a thorough check in under a minute, using only natural light and, optionally, a UV lamp.
Why does this matter when you're handling a $100 bill? Counterfeiters often replicate one or two features—such as printing a static image of the security ribbon or using ink that looks copper—but they cannot reproduce the full set of interactions. A genuine note will pass every check: the thread glows pink under UV light, the watermark appears from both sides when held to light, the ribbon's images move in two directions when tilted, and the colour-shifting ink changes smoothly from copper to green. If any single feature fails, the note is suspect. If multiple features fail, the note is counterfeit.
The Treasury's approach also accounts for wear and handling. Genuine security features remain functional even on circulated bills: the watermark and thread are embedded in the paper and will not fade, the ribbon's motion persists regardless of creases, and the colour-shifting ink retains its optical properties unless the note is severely damaged. This durability means you can apply the same verification steps to a worn bill as you would to a crisp one, and the results should be consistent. When you understand that these features were designed as a system—not as isolated elements—you can verify a $100 note with confidence, knowing that counterfeiters must overcome every layer to produce a convincing fake.
For guidance on verifying other denominations using similar principles, see How to Identify Fake Dollar Bills: Detection Guide.
Common Mistakes and Misconceptions
When verifying the authenticity of a $100 bill, it's easy to overlook certain details or rely on incomplete information. We outline common pitfalls to ensure a thorough check.
Relying on a Single Security Feature
Some individuals may check only one or two security features, assuming that's enough to confirm authenticity. However, counterfeiters often replicate a single feature convincingly. To avoid this, verify multiple features: the 3-D Security Ribbon, colour-shifting ink, security thread, and watermark1.
Ignoring the Security Thread Under UV Light
The security thread glows pink under ultraviolet (UV) light, providing a quick electronic confirmation2. Failing to check this feature can lead to accepting a counterfeit note. If you have access to a UV lamp, always perform this check.
Misjudging the 3-D Security Ribbon
Counterfeiters may print a static image of the ribbon, which doesn't move when tilted. To verify, tilt the note slowly from side to side and up and down; the images should shift smoothly in both directions2. A static image or lack of movement indicates a fake.
Not Checking for Wear and Handling
Genuine security features remain functional even on circulated bills. However, severely worn or damaged notes may show compromised features. Understand that some wear is normal, but significant damage or inconsistent results across multiple features should raise suspicions.
Failing to Compare with a Known Genuine Bill
When possible, compare the suspect note to a known genuine $100 bill. This helps to identify any discrepancies in the security features, such as differences in colour-shifting ink or the clarity of the watermark2.
Key Takeaways
To verify a $100 bill, remember these key steps:
- Check the 3-D Security Ribbon for smooth movement when tilted.
- Verify the watermark of Benjamin Franklin is visible from both sides.
- Ensure the security thread glows pink under UV light.
- Confirm the colour-shifting ink changes from copper to green when tilted.
Next, consider learning how to identify fake dollar bills of other denominations by visiting our guide on How to Identify Fake Dollar Bills: Detection Guide.