How did a walk in the woods lead to Velcro?

Velcro was invented by the Swiss engineer George de Mestral, who noticed burrs clinging to his clothes and his dog's fur, examined them under a microscope, and found they were covered in tiny hooks that caught on loops of fabric or hair. He spent years working out how to reproduce that hook-and-loop mechanism in fabric, settled on nylon, and patented the result in the 1950s. The name combines the French words for velvet and hook. [1] [2] [3]

Most sources place the walk in 1941. Velcro's own history, the Yale Scientific Magazine, the World Intellectual Property Organization (WIPO) and the National Inventors Hall of Fame all give that year. WIPO describes a summer hunting trip in the Jura mountains, while Velcro's company history says the trip was in the Alps. The Smithsonian's Lemelson Center instead dates the walk to 1948, so the sources do not agree on the date. [2] [3] [4] [5] [1]

All of them agree on what he saw. The burrs, from burdock plants, spread their seeds by attaching to passing animals. Under the microscope, de Mestral saw that each burr was covered in small hooks that grab anything with a loop, such as clothing fibres, fur or hair. The National Inventors Hall of Fame calls his approach biomimicry, meaning the copying of designs found in nature. [5] [3] [1]

Turning the idea into a product was slow. WIPO says some people laughed at the idea and that he met technical problems. His design used one strip with thousands of tiny hooks and another with soft loops. He worked with a weaver from a textile plant in France, in Lyon according to Velcro and the Inventors Hall of Fame. The Smithsonian says the development took nearly a decade, and WIPO says nearly eight years. [4] [2] [5] [1]

Early versions used cotton, but nylon proved stronger, wore down less and could be made in different thicknesses. It can be woven into loops and heat-treated to hold its shape. The loops were easy to make. The hooks were harder, and Velcro says de Mestral built a device inspired by barbershop clippers to trim loops into hooks. Yale Scientific describes the hooks as made by cutting the tops of the loops in half. [4] [3] [2]

De Mestral filed a Swiss patent application in 1951, according to WIPO and Velcro, and the patent was granted in 1954. The Velcro trademark dates from the same year. A US patent followed in 1955, along with registrations in Europe and Canada. The Inventors Hall of Fame gives the date of the patent as May 13, 1955. [4] [2] [5]

Mass production needed new machinery. WIPO says de Mestral eventually developed looms and proprietary hook-cutting systems so that every strip fastened equally well. [4]