A designer dressed Chappell Roan with seaweed. But don't expect to find the approach in stores — yet

NEW YORK — At her kitchen stove, fashion designer Caroline Zimbalist looks like an alchemist at work as she stirs a pot full of corn starch and a thickener made from seaweed. The peppermint-scented mixture glitters as she carefully pours it into silicone molds of hearts and leaves.

When the material hardens, Zimbalist will stitch it into unique, made-to-order dresses that she sells on her website. She hopes her designs, which have been worn by celebrities including Chappell Roan, will put a spotlight on materials that aren't sourced from planet-polluting fossil fuels, such as oil.

''It's almost like a vessel to show the world,'' she said.

Other small-scale designers are testing out tapioca, gelatin and other kitchen-shelf ingredients. Meanwhile, big names such as Adidas and Hermes have experimented with mushroom leather, while the Lycra brand is incorporating a new largely corn-based material into stretch fabric. Some experts are skeptical that these textiles — commonly referred to as biomaterials — will go mainstream, but designers such as Zimbalist hope their experiments will set an example for larger brands to follow.

Over 60% of clothing comes from petroleum-based synthetics like polyester, according to Textile Exchange, a nonprofit that promotes sustainable fashion. Manufacturing those materials creates emissions. Synthetic garments can also shed microplastics during washing. And as fast-fashion brands pump out new clothes for customers who expect new designs every few weeks, many garments end up in landfills.

Zimbalist's designs gained attention in 2024 when Roan wore one on ''The Tonight Show.'' The New York-based designer has since dressed stars such as comedian Atsuko Okatsuka and actors Anna Lore and Reneé Rapp. She takes commissions for custom clothing pieces, which cost between $150 and $1,200, via her website, which notes her ''unique recipe of biodegradable and natural materials."

As to whether her approach could be reproduced at a larger scale, Zimbalist says her materials could most practically be used to replace plastic hardware such as buttons and zippers. She acknowledges they can be sticky if not dried correctly, stinky if not treated and melty if exposed to extreme heat.

''Even incorporating it in small ways to start would be really strong,'' she said.

Why biomaterials are hard to find

Fossil-fuel derived fabrics are ubiquitous because they're cheap and made from plentiful raw materials, said Dale Rogers, an Arizona State University professor who studies supply chains.

Many clothes are also made of materials that come from plants or animals such as cotton, silk, wool and cashmere. But some have environmental impacts. Cotton uses a lot of water. Sheep and goats burp out methane.

Some biomaterials have gotten closer to widespread use. Mycelium leather, made from mushrooms, has been used to create luxury shoes, accessories and handbags by brands such as Stella McCartney, Lululemon, Adidas and Hermes.

Still, Rogers said he's not convinced there's enough demand for alternative materials to overcome companies' aversion to the higher costs of producing them at a large scale.

''Honestly, in the end, cost drives almost all decisions,'' he said.

Wrinkles in aiming for sustainability

Getting larger companies to use alternative materials depends on whether they will pay more for a fabric that matches their values, said Jon Veldhouse, the CEO of Qore LLC.

His company makes a product called Qira that replaces about 70% of the fossil-derived components of elastic synthetic fabrics with a corn-based material. The Lycra Company, which sells its stretchy material to major brands, initially expects to incorporate Qira in around 25 percent of its Spandex business, said Lycra chief brand and innovation officer Steve Stewart. But that option will be more expensive, and they haven't yet announced any takers.

It can also be hard to measure the sustainability of farming practices that go into producing raw materials for new fabrics. Cargill is Qore's partner and corn supplier, and it gets its grain from farmers in the vicinity of their processing plant. Veldhouse said many already plant cover crops or reduce tilling to lower environmental impact, but he couldn't provide data on how many use those approaches.

Sarah Needham, a senior director at Textile Exchange, said it's great to see a large organization such as Lycra making its production systems more sustainable. But she also stressed the industry needs to reduce its overreliance on virgin materials, perhaps considering agricultural waste as a source of fabric.

The role of experimental designers

Needham said experimental designers are often the ones coming up with those alternatives to virgin materials and building appetite for new approaches.

But small designers might not have the resources to test the biodegradability of their materials, which often do involve processing, even if it's by hand, said Ramani Narayan, an engineering professor at Michigan State University.

''If I take something — like seaweed or whatever it is — and I apply a process to it, then I can no longer call it natural," he said.

Zimbalist, the New York designer, acknowledges that her materials aren't ready to replace conventional fabrics and that her work is more of ''a piece that leads to larger conversations.''

Rogers, of Arizona State, thinks the fashion industry is a long way from meaningful change, but that ''it's incredibly valuable" for artists and specialty manufacturers to try new materials.

''What they're doing is likely to have long-term benefit, maybe even after their lifetimes,'' he added.

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