Unzipped Origins: The Bizarre, Bumpy History of the Everyday Zipper

Whitcomb L. Judson's 'Clasp Locker' was a commercial disaster at the 1893 Chicago World's Fair. Last week, we pulled apart the hidden science in the objects we use every day, the things that just... work. And it left me thinking about the inverse... the things that were invented, and then failed, for decades, before we ever let them into our lives. The zipper is the perfect ghost of that idea—an invention so obvious now, that was so impossible then. To understand the desperation for something like a zipper, you have to remember a world governed by the button. And the hook-and-eye.

And the lace. A world of painstaking, deliberate fastening. Think of high-button shoes, which could have a dozen or more buttons per boot. Getting dressed wasn't a gesture, it was a project. It was a tyranny of tiny, frustrating discs and loops that demanded dexterity and, more than anything, time. This was the world that Whitcomb L. Judson, an inventor from Chicago, wanted to fix. The story goes that he had a friend with a bad back who couldn't bend over to do up his own boots. And so, Judson didn't set out to revolutionize fashion. He set out to solve a simple, mechanical problem for a friend.

His solution, the one he proudly displayed at the World's Fair, was called the "Clasp Locker or Unlocker for Shoes." It was… not good. It wasn't a zipper as we know it. It was a clumsy series of hooks and eyes, linked together, that were pulled shut by a slider. It was bulky. It was expensive to make. And it had a fatal flaw: it would snag. It would jam. And worst of all, under any real strain, it would pop open. The public at the fair was unimpressed. It was a novelty that didn't work. For twenty years, Judson and his partners at the newly formed Universal Fastener Company tried to sell this flawed device, mostly for mailbags and tobacco pouches.

They were always on the verge of bankruptcy. The real story of the zipper doesn't truly begin with Judson. It begins with the man the company hired in 1906. His name was Gideon Sundback. Sundback was a Swedish-American electrical engineer. He was brilliant. He was methodical. He was brought into this failing company to try and fix Judson's unfixable invention. And there, he met and married Elvira Aronson, the daughter of the plant manager. Then, in 1911, Elvira died. And Sundback, consumed by grief, threw himself into his work. He grieved by solving the problem that had stumped everyone else for two decades.

He tinkered with Judson's hook-and-eye model and got nowhere. It was a dead end. So he threw it out. He started over. He realized the strength couldn't come from a series of individual hooks. It had to come from the parts becoming… one. Interlocking. This is the moment. This is the turn. This is where the thing we know is born. Sundback's breakthrough wasn't one idea, it was two. First, the teeth. He replaced the hooks and eyes with small, identical metal scoops. If you look closely at a metal zipper today, you can still see his design. One side of each tooth has a tiny hollow, a scoop.

The other side has a tiny point, a dimple. When the slider passes over them, it forces the dimple of one tooth into the scoop of the tooth on the opposite side. They lock together. Not just next to each other, but into each other. The force is then distributed across all the teeth, making the connection incredibly strong. But here’s the second, and maybe more profound, innovation. Sundback didn't just invent the zipper. He invented the machine that could mass-produce the zipper. He called it the "S-L" machine. It took spools of wire, stamped out the scoops, clamped them onto a cloth tape at precise, regular intervals, and created the two interlocking halves of the zipper automatically.

Before Sundback, making the fastener was a painstaking artisanal process. After Sundback, it was an industrial one. He hadn't just designed an object; he had designed a system. By 1917, he had perfected the "Hookless No. 2," which is, for all intents and purposes, the modern zipper. So now they had a product that actually worked. But a new problem emerged: who wanted it? The company was still bleeding money. The fashion industry saw it as a piece of crude, industrial hardware. It was for boots and tobacco pouches, not elegant dresses. The first real customer, it turns out, wasn't a fashion house.

It was the U.S. Army. As America entered World War One, the military bought thousands of Sundback's fasteners for soldiers' money belts and for the flying suits of early aviators. In the cold, high altitudes of an open cockpit, fumbling with buttons was not an option. Pilots needed to be able to seal their gear quickly and securely. The "Hookless Fastener" found its first real purpose in the sky. But it didn't have its name yet. That came in 1923, from the B.F. Goodrich company. They decided to use the fastener on a new line of rubber galoshes. An executive, an account man named Bertram G.

Work, was supposedly so taken with the sound the slider made as it sealed the boot… zzzzzip! … that he coined the name on the spot. The "zipper." It was an onomatopoeia. A brand name so good it became the name of the thing itself. Goodrich even trademarked it. For years, you could only technically call a B.F. Goodrich product a zipper. Everything else was a "slide fastener." The name was the final key. It was catchy. It was modern. It sounded fast. And slowly, fashion started to pay attention. The turning point came in the 1930s. The French couturier Elsa Schiaparelli began using brightly colored, oversized plastic zippers as deliberate, decorative elements in her avant-garde designs.

She made the zipper visible. She made it a statement. Then, in 1937, Esquire magazine ran a feature that it called the "Battle of the Fly." It pitted the traditional, multi-button trouser fly against this newfangled zipper. The magazine declared the zipper the winner, praising its convenience, its security, its clean lines. It was hailed as the "Newest Tailoring Idea for Men." The zipper had finally arrived. It had gone from a failed boot clasp to a military tool to a high-fashion statement to an ordinary part of every man's wardrobe, all in the space of forty years. When you really stop and look at it, the zipper is a marvel of material science and mechanical engineering.

The choice of metal—brass, then aluminum, now often nickel or zinc alloy—has to be perfect. It needs to be strong enough to resist deformation, but soft enough to be stamped into shape easily. The cloth tape it’s sewn to, usually cotton or polyester, has to be incredibly durable to withstand the repeated stress of being pulled. And then there's the slider. That little piece we hold is doing three jobs at once. As you pull it up, the Y-shaped channel inside forces the two rows of teeth together at a precise angle, locking them. As you pull it down, a small wedge at the top of the channel pries the teeth apart.

Most modern sliders also contain a locking mechanism, a tiny pin that engages with the teeth when you’re not pulling on the tab, which is why your jacket zipper doesn't just slide open on its own. The most dominant name in this world today isn't American. It's Japanese. YKK. Yoshida Kogyo Kabushikikaisha. That company produces roughly half of all the zippers on Earth. Something like seven billion a year. And their story is the logical conclusion of Gideon Sundback's obsession with process. YKK is famous for its vertical integration. They don't just make zippers. They make the machines that make the zippers.

They smelt their own brass. They forge their own steel for the dies. They spin their own polyester thread and weave their own cloth tape. They even make the cardboard boxes they ship the zippers in. It’s a level of control that ensures every single component is perfect, because a single flawed tooth in a hundred can cause a failure. A single failure can ruin a twenty-thousand-dollar handbag, or worse, a two-million-dollar spacesuit. You probably have three or four zippers on you right now. On your jacket, your pants, your bag. We don't see them anymore. They're just part of the background noise of getting through the day.

But the zipper did more than just make dressing faster. It changed the silhouette of clothing. It allowed for tighter, more form-fitting designs that would have been impossible with buttons. It democratized a kind of sleekness that was once the sole property of custom tailoring. It changed the speed of life, shaving minutes off the beginning and end of every single day for billions of people. It’s a simple machine that embodies a profound idea. Two distinct, rigid rows of teeth, useless on their own, that can be joined by a simple gesture into a single, flexible, and surprisingly strong whole… and then, just as easily, be parted again.

It’s a small, mechanical miracle we stopped noticing a long time ago.