This Is Why Almost All of Your Zippers Have the Letters “YKK” on Them

If you’ve ever inspected your jacket or handbag zippers, you might have noticed that a good majority of them are inscribed with the letters YKK. (Here’s how to use wax paper to fix a broken zipper.) The initials appear on zippers across brands and types of gear—meaning you’re just as likely to find them on an Hermes bag as you are on a scuba-diving suit or a bagpipe. 

Fortunately, there’s not a giant zipper conspiracy. The letters themselves stand for “Yoshida Kogyo Kabushikikaisha.” From Japanese, that translates to “Yoshida Company Limited.” And as you’ve likely guessed by now, the company is a massive zipper manufacturer, making roughly half of the zippers on earth. In layman’s terms, that’s about seven million zippers each year.

So why has no one stepped in and challenged YKK? To put it simply, designers trust the brand and have since 1934. “YKK makes incredibly dependable zippers, ships them on time without fail, offers a wide range of colors, materials, and styles, and never gets badly undercut on price,” writes Seth Stevenson on Slate.

And yet surprisingly, YKK didn’t invent the zipper. That accolade goes to Whitcomb L. Judson, who created the “chain lock fastener” in America in the 1890s. The company still exists as Talon, Inc, and is used by brands such as Brooks Brothers and Uniqlo.

YKK stepped onto the scene when founder Tadao Yoshida decided he wasn’t satisfied with existing production methods. In his factory, every aspect of production takes place in-house. As the Los Angeles Times explains, “YKK smelts its own brass, concocts its own polyester, spins and twists its own thread, weaves and color-dyes cloth for its zipper tapes, forges and molds its scooped zipper teeth.”

With that level of detail and control, it’s no wonder the zippers have taken over. “There have been quality problems in the past when we’ve used cheaper zippers,” designer Trina Turk told Slate. “Now we just stick with YKK. When the customer is buying $200 pants, they better have a good zipper. Because the customer will blame the maker of the whole garment even if the zipper was the part that failed.”

Before you purchase your next expensive piece, don’t miss these 8 tricks to spot a well-made item of clothing. “A zipper will never make a garment,” says Turk. “But it can break a garment.”