U.S. paper money is made from a blend of 75 percent cotton and 25 percent linen, not the wood-pulp paper used in books, newspapers, or printer sheets. This specialized fabric-like material is why a bill that accidentally goes through the washing machine comes out mostly intact while a regular piece of paper disintegrates.
Why Cotton and Linen, Not Wood Pulp
Ordinary paper is made from wood fibers that break down quickly with moisture, folding, and handling. Cotton and linen fibers are far more durable. The cotton used in currency paper comes from fibers too short to be spun into textile threads, essentially a byproduct of the cotton industry repurposed for a much more demanding job.
The resulting material feels distinctly different from anything you’d run through a printer. It’s crisper, slightly textured, and more resilient. You can fold a bill thousands of times before it tears, something no wood-pulp sheet could survive. Crane Currency, which has supplied paper to the U.S. Treasury for over a century, applies a proprietary surface treatment that further boosts mechanical strength, improves how well the paper holds ink, and creates a barrier against soiling and moisture.
Security Features Built Into the Paper
Several of the anti-counterfeiting features on U.S. currency aren’t printed on the surface. They’re embedded directly into the paper during manufacturing, which makes them nearly impossible to replicate with commercial equipment.
- Red and blue fibers: Tiny synthetic threads of various lengths are distributed throughout every bill. You can see them scattered across the surface if you look closely. These are woven into the paper itself, not printed on.
- Security thread: On denominations of $5 and above, a thin strip is embedded in the paper. You can see it when you hold the bill up to light. Its position shifts depending on the denomination, so a counterfeiter can’t simply bleach a $5 and reprint it as a $100.
- Watermark: Bills of $5 and higher also contain a faint image visible when held to light, positioned to the right of the portrait. Like the security thread, this is part of the paper, not the printing.
- 3-D security ribbon: On the $100 bill, a blue ribbon is physically woven into the paper. Tilting the note causes images on the ribbon to shift, a feature that relies on the paper’s structure rather than surface ink.
This layered approach is what makes currency paper so specialized. A counterfeiter working with store-bought cotton paper might approximate the feel, but reproducing embedded threads, shifting ribbons, and watermarks requires the actual papermaking process.
How Long Currency Paper Lasts
The cotton-linen blend holds up well, but different denominations wear out at very different rates based on how often they change hands. A $1 bill gets passed around constantly at coffee shops and convenience stores. A $100 bill tends to sit in a wallet, a safe, or a bank vault.
The Federal Reserve tracks estimated lifespans for each denomination. A $1 bill lasts about 7.2 years. The $5 and $10 wear out faster than you might expect, at 5.8 and 5.7 years respectively, likely because they circulate heavily in everyday cash transactions. The $20 lasts around 11.1 years, the $50 about 14.9 years, and the $100 bill has the longest life at roughly 24 years. When bills become too worn or damaged, the Federal Reserve pulls them from circulation and shreds them.
Some Countries Use Plastic Instead
Not every country prints money on cotton-based paper. A growing number of nations have switched to polymer banknotes, which are made from a thin, transparent plastic film. Australia pioneered the modern version in the late 1980s and became the first country to issue a full set of polymer notes in 1996. Romania followed in 1999 as the first European country to make the switch, and dozens of others have adopted polymer for at least some denominations since then. Canada and the United Kingdom are among the most prominent countries now using polymer bills.
Polymer notes last significantly longer than cotton-based ones, resist moisture and tearing better, and are harder to counterfeit because the transparent windows and holographic features in the plastic are difficult to reproduce. They also stay cleaner. The tradeoff is that they can be damaged by high heat and feel unfamiliar to people accustomed to the texture of traditional currency.
The U.S. has so far stuck with its cotton-linen blend, partly because the existing security features are deeply integrated into the paper manufacturing process, and partly because the infrastructure for producing, sorting, and handling cotton notes is well established across the country’s banking system.
Why You Can’t Replicate It at Home
Even knowing the 75/25 cotton-linen ratio doesn’t get a counterfeiter very far. The specific fiber lengths, the embedded security features, the proprietary surface treatments, and the precise thickness and texture of genuine currency paper are controlled at every stage of production. The paper is manufactured under contract with the federal government, and its sale to anyone outside the Bureau of Engraving and Printing is illegal. Combined with the advanced intaglio printing process used to apply the ink (which creates the slightly raised texture you can feel on a genuine bill), the paper itself is one of the strongest lines of defense against counterfeiting.