February 13, 2024

Sway Unveils First Scalable Seaweed-Based Plastic Packaging Alternative, Following Close of $5M Seed Round


Above – Thermoplastic Seaweed Resin (TPSea), made entirely from seaweed and plants. Photo by SnackTime.

SAN LEANDRO, CASway, the California-based startup creating seaweed-based, home compostable replacements for plastic packaging, has revealed a breakthrough technology that, for the first time, will enable seaweed to replace flexible plastics at scale. Representing an entirely new category of biopolymer resin, Sway’s patent-pending Thermoplastic Seaweed resin (TPSea™) is a 100% biobased, home-compostable, microplastic-free ingredient made from a regenerative ocean crop that can replenish ecosystems and support coastal communities.

Sway’s new technology is designed to mesh seamlessly with the most scaled plastic manufacturing systems available, enabling growth and massive impact. The packaging sector is the largest generator of single-use plastic waste ­in the world. Sway’s evolving product portfolio made with TPSea™ includes flexible packaging applications such as polybags, retail bags, and food wrappers for consumer brands, representing approximately 30% of all single-use plastic packaging.

This launch accompanies Sway’s successful $5 million seed round led by Third Nature Investments and includes investment from The Helm, Alante Capital, BAM Ventures, Superorganism, and other industry-aligned investors. The funds will directly support the scaling of Sway’s product portfolio, and catalyze adoption by fashion, food, and home goods brands such as J.Crew, Burton, and others associated with the TOM FORD Plastic Innovation Prize.

“Clean oceans, abundant biodiversity, and thriving coastal economies all intertwine with Sway’s success as we accelerate production in 2024,” says Julia Marsh, CEO & co-founder of Sway. “We believe everyday materials should help to replenish the planet from sea to soil. The launch of our thermoplastic seaweed materials, along with an influx of new capital targeted at scaling production, signifies tangible progress toward a more circular future.”

Sway’s seaweed materials provide all the technical performance brands want, while adding ecological and societal value along the way – unlocking new, streamlined paths to reducing plastic pollution and broadening access to biologically degradable materials. TPSea™ resin, rolls of film, and finished packaging are now available to packaging manufacturers and consumer brands for adoption.

“Our expansive network of eco-conscious brands are always looking for restorative alternatives to today's mainstream packaging materials. We see this demand across all industries, from food to fashion to cosmetics,” says Saloni Doshi, CEO of EcoEnclose. “With tangible shifts in customer values, brand sustainability commitments, and packaging legislation, it’s clear that innovation leaders like Sway have a keen market ready to adopt their truly unique, thoughtfully produced, biobased materials.”

The company first debuted their thermoplastic seaweed collection in January in Paris at Biofabricate 2024, the foremost gathering of the world’s innovators, brands and investors leading the transition to a biomade future. This milestone follows a momentous 2023, in which Sway won first place in the TOM FORD Plastic Innovation Prize powered by Lonely Whale. The Prize helped validate Sway’s product and business model across scale, cost, performance, biological degradation, and environmental & social impact metrics.

“Regenerative practices and sustainable packaging are active focus areas for J.Crew Group,” says Doug Forster, Chief Sourcing Officer at J.Crew. “We’re thrilled to see Sway’s steady progression toward market-scale production that will empower brands like ours to transition into next-generation materials."

Sway Seaweed Polybags

Above – Sway's new line of polybags made from TPSea Flex™ film. Photo by SnackTime.

About Sway

Sway is a cleantech startup scaling seaweed-based, rapidly compostable replacements for plastic, beginning with flexible packaging. Their patent-pending products match the vital performance attributes of conventional plastics and are designed to plug into existing infrastructure, enabling scale and massive impact. Unlike plastic, however, their materials are made from an abundant, regenerative resource and decompose into healthy soil after use.

In 2023, Sway won first place in the TOM FORD Plastic Innovation Prize. In 2021, Sway also won the Beyond the Bag Challenge sponsored by Closed Loop Partners and a consortium of major retailers. As a member of the Sustainable Packaging Coalition, the Sustainable Ocean Alliance, and 1% for the Planet, Sway is working holistically to scale their product for a thriving, equitable future. 

Sway is headquartered in the California Bay Area. To learn more, visit

For media inquiries, contact Alyssa Pace at

Copyright © 2024 Sway Innovation Co. - All Rights Reserved.