One size doesn’t fit all, and that definitely includes the face masks that we’ll all likely be wearing every day for the next year or more. Facial shapes and sizes vary considerably from one adult to another, after all, so buying masks online is a bit of a crapshoot — especially since stretchy fabrics tend to be less comfortable than standard ones.

Engineer Ryan Mario Yasin recently came up with a smart solution to this problem: a permanently pleated fabric that expands and contracts over your features for a custom fit. If BETA[MSK] looks a bit futuristic, that’s probably because it’s ahead of its time even when it comes to textile innovation.

Sustainably made from recycled PET plastic bottles using a patent pending technology and waste-reducing patterns, the BETA[MSK] is a form-fitting face covering that’s adjustable enough to fit the vast majority of adult faces. The pleats are engineered to be hard-wearing, so they’ll bounce back to their original tight formation even after they’ve stretched many times.

The mask secures in the back with quick-release velcro, so it’s very easy to put on and take off, and you can wear it like a cuff around your neck when it’s not in use. Just put it on and pull at the pleats until it’s securely covering your nose, mouth, and chin. The mask also features a filter pocket for PM2.5 carbon filters (two of which are included with purchase), along with a form-fitting removable nose wire. Offered through Yasin’s company Petit Pli, the BETA[MSK] already sold out two previous batches, but there’s a waitlist up for the next round.

As you might imagine, this textile has some other convenient uses, too. Yasin first developed it when he realized his young nephew was rapidly growing out of his clothes, and constantly repurchasing bigger sizes just felt like a waste. Before pivoting to masks during the pandemic, Petit Pli was primarily a children’s clothing shop offering adorable pleated waterproof and windproof outerwear that stretches as kids grow, helping them last longer.

The company’s official website reads: “Inspired by aerospace engineering, Petit Pli’s continuous size adjustment is a new way of approaching garment design — one suitable to high growth rates in children. Petit Pli uses technical materials that are ultra-lightweight, reinforced, rainproof, and breathable because children are extreme athletes.”

“The Petit Pli BETA[MSK] is made from recycled fabrics and has a monofiber construction. Through its approach towards sustainability and innovation, Petit Pli hopes to instill slow-fashion values in humans whilst designing for the needs of humanity — little and tall. We aim to inspire humanity to value longevity and innovation in some of the most intimate products in our lives — garments. The Petit Pli Beta[MSK] is made in London, supporting our local supply chain.”

The company adds that: “The BETA[X] range signals a Petit Pli research project made in limited quantities in London. If feedback is positive, the project progresses onto the next stage. This ensures we do not overproduce and waste resources. We want to design the best garments possible for you, with you. Constructive criticism from BETA[X] owners is welcomed to help evolve the garment.”