Seaweed

Seaweed fabric is an emerging class of bio-based textiles derived from sustainably harvested macroalgae. It is not a single material but two distinct technological pathways: SeaCell by smartfiber AG, which embeds seaweed powder into a closed-loop Lyocell process, and Kelsun by Keel Labs, which uses marine biomass as the primary feedstock and eliminates wood-based cellulose entirely. Both offer brands a pathway to reduce reliance on land-intensive crops and fossil-based synthetics.

Seaweed grows without land, freshwater, or fertilizers, and responsible harvesting leaves root systems intact. When processed via closed-loop systems, the environmental profile is strong. One honest caveat: wellness claims around minerals and antioxidants should be treated cautiously, as these compounds are not retained in a measurable way once the fiber is processed.

For brands, the key sourcing risk is greenwashing. "Seaweed fabric" is a generic term. Always name the specific technology and supplier, verify closed-loop processing, and minimize blending with synthetics to preserve biodegradability. Look for OEKO-TEX Standard 100 on finished goods.