Meet the artist who turns tennis balls into furniture

(CNN) — Over the past two years, tennis has invaded our closets (court-appropriate outfits can be found everywhere from Skims to Miu Miu), our screens (who could forget Zendaya’s role as tennis protege turned elite coach Tashi Duncan on “Challengers”) and now — our living rooms.

At least that’s what Belgian designer Mathilde Wittock, who makes custom furniture from used tennis balls, hopes. Wittock’s sleek, modernist lounge chairs are entirely cushion-free, save for the padding of 500 carefully arranged tennis balls. Her metre-long benches are similarly pared-back, with some 270 balls that are both elegant and structurally sound.

“It takes about 24 different manufacturing steps to make a tennis ball, which takes about five days. Then it has a very short lifespan,” Wittock told CNN in a video call from Brussels. “I got interested in tennis balls because I played tennis myself, so I know there’s a lot of waste.”

About 300 million tennis balls are produced each year. Nearly all of them end up in landfills, where they take more than 400 years to decompose. The U.S. Open, which ended this weekend, uses about 70,000 a year, followed closely by Wimbledon, at 55,000 balls. Wittock estimates that the life cycle of a ball is only nine games, depending on the level of play. “Even if they’re in their can, if the can has been opened, the gas in the tennis balls will release over time,” she said. “(Eventually) they’ll flatten out and you’ll have to throw them away.”

It takes Wittock about three to four weeks to make a chair, which she sells for $2,900. Each ball is hand-cut and hand-dyed, with colors chosen specifically to fit the client’s space. It took a lot of trial and error to master the ball’s shape while masking some of its easily recognizable features. “I needed to find a combination that would change the iconic look of tennis balls,” she said. “It’s yellow and has these white lines. How can I distort that relationship?”

Wittock began to see the possibilities of designing these sports equipment while studying at Central Saint Martins art school in London. “I was really interested in eco-design and where my materials were coming from,” she told CNN. “And I realized that it was always really complicated to track the history of materials. You never know where they came from or how they were treated. That really made me angry.”

Today, she receives all her equipment thanks to donations from tennis clubs. The collections started small – sometimes with just 10 balls at a time – but they quickly grew. Today, Wittock works with the Wallonia Federation in Brussels, which has donated its entire stock – around 100,000 balls. How long will this last? “It’s enough for a few months,” she says. “If things go wrong. Maybe nine months, because I have a rhythm of cutting tennis balls. I can cut 1,800 a week.”

But creation isn’t the only goal. In fact, what matters most to Wittock is how her pieces are disposed of. “I’m an eco-designer,” she says. “Eco-design is about circularity. You can use good low-carbon or recycled materials, but you have to think about the end cycle. If it’s not a circle and you can’t reuse (the elements) for something else, it’s not eco-design. It’s even worse, because they’re new materials.” At the end of her furniture’s life, Wittock can disassemble the hundreds of tennis balls (which are woven together without glue) for recycling, where the fluff is burned and the rubber shredded to make inflatable play mats.

His next challenge? Appealing to the tens of thousands of tennis clubs in North America. “I have so many people interested in the United States,” Wittock said. “I’m definitely considering coming down there and starting to recycle there.” So the next time you watch a tournament, don’t lament the discarded balls: Their life cycle may just be beginning.