Made in three minutes, feels like a sock: Are spray-on sneakers the future?

The unconventional shoe is the result of a new technology that sprays the upper part of the sneaker onto a foot-shaped mold twirled around by a robotic arm.

The LightSpray system not only produces an unusual shoe but eliminates the need to source and stitch together individual pieces of fabric. A sneaker materializes in about three minutes using the technology, a step toward automating an industry that still relies heavily on human labor.

“In a traditional product you have 200 pairs of hands, in this one you basically have only a few,” said Marc Maurer, On’s co-chief executive.

The first commercial sneaker produced using the spray is the CloudStrike Boom LS—a lightweight, laceless shoe costing $300 a pair and targeted at serious runners. That price is roughly the same as Nike’s latest super shoe and cheaper than a rival offering from Adidas. On now plans to scale up the LightSpray technology to launch cheaper versions of the running shoe as well as casual sneakers in the next few years.

Expanding LightSpray brings challenges. The technology is an exciting development, “but it won’t be a game changer unless they can make it affordable” by using it to make mass-market sneakers, said Matt Powell, a footwear consultant with Spurwink River, citing the initial product’s price tag.

There is also no guarantee consumers will warm to the sneakers. While generally positive about its feel and performance, some early reviews of the shoe noted that it can be tricky to get on and expressed concerns about how its sock-like structure would hold up over time.

Maurer said the shoe’s look may well prove divisive but that making a splash with a distinctive product is preferable to launching something that fails to turn heads.

On is one of several fast-growing sneakers brands—Deckers-owned Hoka is another standout example—that are turning the screw on Nike and Adidas by winning market share.

Most major sneaker brands claim to champion innovation. Adidas and Nike have both made superlight running shoes worn by athletes who broke marathon records in the past year or so. But both shoes are assembled in the conventional way.

For a relative newcomer like On, creativity is more vital than it is for incumbents, Maurer said. Whereas Adidas has the Samba and Nike has the Air Force 1—tried-and-tested styles that can be endlessly relaunched—“we have no archive of old stuff,” he said.

On began in 2010 as an experiment when Swiss triathlete Olivier Bernhard chopped up a garden hosepipe and glued the pieces onto the soles of his running shoes to provide extra cushioning. That idea ultimately became On’s CloudTec sole; perforated with large holes, it is visually different from rival sneakers, a quality that helped the brand’s shoes to stand out.

‘You do, we pay’

Having built a reputation for its unusual sole, On wanted to mix up the upper part of sneakers too.

The LightSpray project started in 2019 when one of the company’s developers spotted student Johannes Voelchert at the Milan Design Show demonstrating a hot glue spray he had adapted from a children’s Halloween toy. Instead of squirting stringy spider’s webs, it was now being used to create complex three-dimensional forms.

Seeing the spray’s potential, On hired Voelchert as an intern and set him up in the company’s “maker space,” where he worked alone trying to figure out if he could produce a shoe.

“We just said, ‘You do, we pay,’ and we gave Johannes his corner upstairs and a robot arm,” said Ilmarin Heitz, On’s senior director of innovation.

After a year of research, On recruited a 20-strong development team, only three of whom had any experience as footwear designers. The group included material scientists, 3D-modeling experts and robotics specialists—people with the skills to develop a new production process. Voelchert graduated from intern to senior lead for innovation technology design.

Fine-tuning the spray was an arduous process. The upper part of the sneaker is made from synthetic materials known as polymers, which behave differently depending on how they are combined, heated and sprayed. The team tried hundreds of combinations before finding a formula that was durable but also flexible and comfortable.

To make the shoe, a single mile-long polymer filament is sprayed onto a standard mold. First, it is bonded to a pre-manufactured sole and then the material is layered up until the upper is fully formed. Colors and logos are then laser-printed onto the shoe.

Voelchert said the process can be further refined, cutting the production time from three minutes per shoe down to two. The team is also working on honing the technology to produce a complete sneaker, including the sole.

Though large factories can produce conventional shoes at a high rate, LightSpray promises to simplify the process by condensing the supply chain to a single input, the polymer, and cutting most human workers out of the loop. Machines could be distributed globally, ending the costly and time-consuming practice of shipping products from Asian factories.

On has only two LightSpray machines but plans to add more so it can start producing in higher volumes.

The daily ‘runch’

On put its new shoe to the test this spring, sending a pair to Kenyan athlete Hellen Obiri ahead of April’s Boston Marathon.

“I was suspicious, I had big doubts,” Obiri said, recalling her reaction upon seeing the sneaker for the first time. Obiri then ran a personal best in her first training session wearing the LightSpray shoes.

Obiri went on to win the Boston Marathon wearing the sneakers, before scooping a bronze medal at the Paris Olympics.

A limited commercial drop of the sneakers followed this summer and several hundred more pairs are due to be released this month. On hasn’t disclosed sales figures but says tens of thousands of people have registered their interest in buying the shoes.

In the company’s early days, On’s founder took retailers out running to convince them its unusual-looking shoes actually worked.

By 2019, Swiss tennis star Roger Federer was an investor.

On’s big break came during the pandemic when big brands like Nike abandoned retailers to sell more products directly to consumers online. The sneaker maker rushed to fill the shelf space and snapped up spare production capacity as rivals dialed back their output.

The company’s sales rose 47% to roughly $2.1 billion last year, with net profit up 38% to about $92 million. Two-thirds of sales are generated in the U.S., where On listed in 2021.

On’s headquarters is in Zurich. Some staff commute in summer by swimming along the Limmat River—towing their clothes, phones and laptops in protective dry bags—and share daily “runch,” a riverside run followed by lunch in the vegan canteen.

Earlier this year, Kris Hartner, who runs Naperville Running, a chain of sports stores in Illinois, became one of the first people to get his hands on the LightSpray shoes.

Hartner has seen hundreds of sneaker styles over the years, but “there’s never been anything like this,” he said. “It’s a great time to be a shoe geek!”

Write to Trefor Moss at [email protected]