PARIS — Under the glass dome of the Grand Palais, designer Eugène Riconneaus unveiled his first dress that could mark a turning point in sustainable fashion. The couture piece is made from a scalable, seaweed‑based textile developed through his ER Ocean Recherche project.

He titled the look “Ocean Apocalypse,” but the dress is more than a boldly named statement. It’s Ricconeaus’ personal proof of concept that his deep dive from design into materials R&D has paid off.

The dress stood alongside fluffy bowls of SeiFibre and SeiYarn, ocean-derived fibers produced using marine biomass that Riconneaus began developing during the pandemic. The process converts algae and cyanobacteria into his proprietary Sei, a nano-structured marine material. Sei can then be transformed into textile fibers for yarns and fabrics, coated canvases and more.

The result at ChangeNow was tufts of soft fiber and rolls of spun yarn, as well as a series of T-shirts and fabric samples that showcased the material’s quality and versatility, from thin silk-like textures to sturdy, thick jersey. The material is now ready to move from laboratory to industry.

While still in early commercial stages, the fibers have been integrated into different weaves and blends with plant-based materials, performing well in independent testing, including demonstrating antibacterial properties, he noted.

Unlike many lab innovations that get stuck in prototype form, Sei has a clear path to scale, Riconneaus told WWD.

Partnerships with mills and textile producers in Lyon, France; Portugal, and other European centers mean the material can be spun and woven at volumes that are meaningful to designers and brands.

“We need to bring designers into the lab,” he said, so they can communicate key aesthetic elements like look and feel to co-develop materials that are functional and desirable. Its potential could empower designers to lead innovation and creativity, rather than waiting for technology to trickle down from industry.

As a designer, his own inability to find acceptable materials was a key driver for his work, he added.

The flatness of his ER Ocean Recherche organization, where he communicates with the science team via WhatsApp, increased the urgency — and excitement — in the lab. “When you manage the science team, and they know they are going to work for a dress that will exist, and they already see the prototype — it’s very concrete,” he said.

That close-knit ethic extends to other brand teams that are currently experimenting with the material, who are able to provide immediate feedback.

He also said brands need to be active in development to push suppliers forward. “[Suppliers] need more work and are so busy looking for more orders that they don’t do innovations. Then we have us — the innovators or scientists. We go to meet them and say, ‘Look, we have the technology, we can drive the whole system, and we work together.’”

The seaweed-based fiber is being tested across a spectrum of applications — from casualwear to complex weaves — and can be blended with cotton, lyocell, cashmere or wool. Early versions have been produced in white or with color integrated during fiber production, and Riconneaus noted ongoing work to refine dyeing processes without compromising the fiber’s properties. The T-shirts on display were in a bright yellow and chalky khaki.

“It’s about making innovation visible, desirable and legible to brands,” he said.

He also hinted that the couture dress is not just a one-off. He is currently planning to return to fashion and is working on a larger collection created with the Sei materials to present during Paris Fashion Week.