The Jantzen Story: A Century of Fit, Built on One Simple Idea

It started with a request from a rower who just wanted his pants to stay up.

In 1910, in downtown Portland, Oregon, three men—Carl Jantzen, John Zehntbauer, and Roy Zehntbauer—opened a small knitting company. They made wool sweaters, gloves, and hosiery. The first day’s receipt was thirty-five cents for a pair of garden gloves. Big things rarely start big.

Then, in 1913, a member of the Portland Rowing Club walked in with a simple problem. He wanted a pair of rib-stitch rowing trunks that would stay up without a drawstring, something fit for cold-morning paddling on the Willamette River. The company made them. The design worked. And that one request quietly became the foundation of modern swimwear.

The “bathing suits” that followed were made of 100% virgin wool, knit on the same machines used for sweater cuffs. They came with matching stockings and a cap. They were heavy, but they worked—and people started asking for “those Jantzens” by name. By 1918, the company had officially become Jantzen Knitting Mills.

Then came the Diving Girl—and a slogan that changed everything.

In 1920, a red-suited diving girl appeared on the Jantzen catalog. She was designed by freelance artists Frank and Florenz Clark, and she quickly became one of the most recognizable advertising icons in American fashion. Billboards featuring her lined the highways leading to beaches in San Francisco, Los Angeles, and Portland. Windshield decals became so popular that Boston banned them in 1924—drivers were too distracted.

By 1921, Jantzen ads were running in Vogue and Life. And in 1923, the brand introduced a slogan that captured exactly what it had done: “The suit that changed bathing to swimming.” It wasn’t just marketing. It was true. Jantzen had helped turn a heavy, restrictive chore into something people could actually enjoy.

War came. Jantzen answered.

During World War II, the company temporarily shifted production away from swimwear. The knitting machines that made bathing suits were used to make sweaters, sleeping bags, and parachute bags for the military. When the war ended, Jantzen returned to swimwear with new materials—nylon and elastic fibers—that changed silhouettes and improved fit all over again.

From Portland to the world.

The 1950s brought resort culture, global travel, and a hunger for international style. In 1956, Jantzen launched the “International Set”—a collection developed by eighteen design studios around the world. By the 1960s, the brand’s cheerful campaign “Just Wear a Smile and a Jantzen” was bringing smile contest winners from across the country to Hawaii.

The Diving Girl evolved over the decades—losing her cap and stockings, becoming more streamlined—but she never disappeared. She remains one of the longest-lived apparel icons in advertising history.

The thread that runs through it all.

Fashion changed. Fabrics changed. What women wanted from swimwear changed. But Jantzen’s obsession stayed the same: fit.

From that very first rowing suit, designed to stay in place without a drawstring, the brand has been built around one belief—that swimwear should work with a woman’s body, not against it. Today, that shows up in thoughtful details like hidden underwire, adjustable straps, and supportive silhouettes that feel personalized to you. It shows up in extended and plus sizes, because great fit isn’t a privilege for some bodies—it’s for every body.

Over a century later, Jantzen is still making swimwear that fits. Not because it’s a trend, but because it’s the only thing that has ever mattered.

Jantzen. Made to fit, since 1910.