Ever held a C-note up to the light? It's a weirdly satisfying ritual. You’re looking for that ghostly face staring back at you from the empty space on the right. That’s the 100 dollar bill watermark, and honestly, it’s one of the most underrated pieces of technology in your wallet. People think everything is digital now, but the U.S. Bureau of Engraving and Printing (BEP) still relies on 18th-century physics to keep the global economy from face-planting.
Cash isn't dead. Far from it.
Even in a world of tap-to-pay and crypto, the $100 bill remains the most frequent target for counterfeiters worldwide. It's the king of currency. If you're going to risk jail time, you aren't doing it for a five. Because of that, the security features on the Benjamin are incredibly dense. The watermark isn't just a "picture in the paper." It’s a structural change to the currency itself.
The weird science behind the 100 dollar bill watermark
Most people think the watermark is printed on. It isn't. If you try to print a watermark, you just get a blurry mess that sits on the surface. A real 100 dollar bill watermark is actually created during the papermaking process.
The paper used for U.S. currency isn't even paper, really. It’s a blend of 75% cotton and 25% linen. While that slurry is still wet, a cylindrical roll called a dandy roll presses a design into the fibers. This makes certain areas thinner and others thicker. When the "paper" dries, those variations in density change how much light passes through. That’s why the image is invisible until you hold it up to a lamp or the sun.
It’s an analog solution to a high-tech problem.
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Does the face match?
Here is where most people mess up. They see a face and think, "Cool, it's real." Nope. You have to look at whose face it is. Since 1996, the watermark on the $100 bill has been a portrait of Benjamin Franklin.
Wait. Why does that matter?
Because of "bleaching." Scammers take a genuine $5 bill, soak it in chemicals to strip the ink, and then print a $100 design on top of the authentic paper. It feels real. It passes the "counterfeit pen" test because the starch-free paper is legit. But when you hold it to the light, you’ll see Abraham Lincoln’s face in the watermark instead of Ben Franklin’s. It’s a dead giveaway. If the faces don't match, you're holding a very expensive piece of trash.
Why the 2013 redesign changed the game
Back in October 2013, the Fed released the "New $100 Note." It was a massive headache to produce. In fact, they delayed it for years because of "creasing" issues during printing. But when it finally hit the streets, it brought a level of security that made the old 1990s versions look like Monopoly money.
The 100 dollar bill watermark remained a staple, but it was joined by the 3D Security Ribbon.
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That blue stripe in the middle? It’s not printed. It’s woven into the paper. It contains nearly a million "micro-lenses." When you tilt the bill, you see bells changing to 100s. It’s wild. But even with that flashy blue ribbon, the BEP kept the watermark. Why? Because the watermark is the "low-light" test. You don't need a UV light or a magnifying glass. You just need a window.
Subtle details you probably missed
- The watermark is visible from both sides of the bill.
- It shouldn't be "sharp." Real watermarks have soft, graduated edges because they are formed by fiber density, not ink.
- In the Series 2004 and newer notes, there is also a security thread (a thin plastic strip) that glows pink under UV light.
If you see a watermark that looks like it was drawn with a grey marker, or if it's only visible on one side, get rid of it. Or better yet, call the Secret Service. Seriously.
How to spot a "sophisticated" fake
Counterfeiters have gotten better. Some now try to simulate the 100 dollar bill watermark by printing a faint image on the inside of two very thin pieces of paper and gluing them together. It’s clever. Sorta.
But it fails the "feel" test. These bills are usually too thick or feel "bubbly" because of the adhesive. Real currency paper is pressed with tons of pressure. It’s crisp. It has a specific "snap" when you flick it.
The Secret Service, which was actually created to fight counterfeiting long before they were guarding presidents, suggests a multi-point check. Never rely on just the watermark. Look for the "Bell in the Inkwell." There’s a copper-colored inkwell on the front of the $100 bill. Inside it is a green bell. When you tilt it, the bell shifts from copper to green, making it appear and disappear.
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If the watermark is there, but the bell doesn't change color, you’ve got a problem.
Practical steps for handling large cash
If you’re selling a car on Facebook Marketplace or handling a large cash transaction, don't feel awkward about checking the money. People who have nothing to hide won't care.
- The Light Check: Immediately hold the bill to the light. Look for Ben on the right side. Check that he looks like the main portrait.
- The Texture Check: Run your fingernail over Ben Franklin’s shoulder. You should feel "raised printing." It’s a texture you can’t get from an inkjet printer.
- The Ribbon Check: Move the blue 3D ribbon back and forth. The bells and 100s should move in a different direction than the way you are tilting the bill.
- The Thread Check: If you have a cheap UV flashlight (you can get them for $10), shine it on the bill. The vertical thread to the left of the portrait must glow bright pink.
If a bill feels "waxy" or "greasy," it’s likely a fake. Genuine currency paper is basically clothes. It's fabric. It should feel like a sturdy, high-quality textile.
What to do if you find a fake 100
Don't try to spend it. That’s a felony. Even if you "didn't know," trying to pass a counterfeit bill can land you in a windowless room explaining yourself to people in suits.
Instead, take the bill to your local bank or a police station. They can verify it. If it’s fake, you’re out the $100, which sucks. There is no "reimbursement" for getting duped by a counterfeit. But it’s better than the alternative.
Keep an eye on the 100 dollar bill watermark. It’s the simplest, oldest, and arguably most effective tool we have to keep "funny money" out of our pockets. It’s not just a ghost in the paper; it’s the backbone of the entire physical monetary system.
Next time you get paid in cash, take three seconds. Hold it up. Find Ben. Check his face. It’s the easiest way to make sure your hard-earned money is actually worth more than the paper it’s printed on.