Why Your US Paper Money Isn't Actually Paper
If you accidentally wash a U.S. dollar bill, it usually survives the spin cycle intact. That is because American banknotes are not made of wood pulp paper. Instead, they are composed of a durable blend of 75 percent cotton and 25 percent linen. Synthetic fibers are also dispersed throughout to prevent counterfeiting, creating a highly resilient material that can bend thousands of times before tearing.
The Fabric Behind the Dollar
Everyday paper is manufactured by breaking down wood chips into a wet slurry of cellulose fibers, which are then pressed flat and dried. While this wood-pulp paper is inexpensive and ideal for newspapers, books, and receipts, it has a major structural weakness: moisture readily breaks the hydrogen bonds holding the wood fibers together. When a standard receipt or sheet of notebook paper meets a washing machine or even a spilled glass of water, it quickly dissolves into a soggy pulp.
Banknotes issued by the Federal Reserve avoid this fate because they are not made of wood pulp at all. Instead, United States currency is printed on a specialized textile substrate composed of 75 percent cotton and 25 percent linen. This rag-fiber blend produces a material that behaves far more like a piece of tightly woven canvas than a page torn from a notebook, allowing bills to survive accidental wash cycles, heavy creasing, and years of physical handling.
Built to Endure Everyday Handling
The physical resilience of cotton and linen fibers gives U.S. currency exceptional tensile strength. Cotton fibers are naturally long and flexible, while linen fibers provide stiffness and structural integrity. When pressed and bound together, these intertwined vegetable fibers form an interlocking matrix that can be folded thousands of times before the structural integrity degrades enough to cause a tear.
This durability is essential given the harsh mechanical stresses banknotes encounter. Cash is repeatedly shoved into wallets, crumpled into pockets, passed through vending machine rollers, and subjected to body heat, sweat, and friction. Lower-denomination bills such as the one-dollar and five-dollar notes circulate rapidly and experience high friction, while higher denominations like the one-hundred-dollar note generally see less transactional use and remain in circulation longer before becoming too worn for machine sorting.