Researchers in South Korea have successfully reproduced a rare golden fabric known as sea silk, lost for over 2,000 years. Using threads from a farmed clam, the team not only revived the material but also explained its enduring shimmer. This breakthrough promises sustainable alternatives to traditional textiles.
A team of scientists from Pohang University of Science and Technology (POSTECH) has brought back sea silk, a luxurious fiber once reserved for ancient emperors and religious figures. Led by Professor Dong Soo Hwang from the Division of Environmental Science and Engineering and Professor Jimin Choi from the Environmental Research Institute, the researchers used byssus threads from the pen shell clam, Atrina pectinata, which is commonly farmed in Korean coastal waters for food.
Sea silk, dubbed the 'golden fiber of the sea,' originated from the Mediterranean clam Pinna nobilis more than 2,000 years ago during the Roman era. Prized for its lightweight strength and luminous gold hue, it adorned powerful individuals, including popes, and features in relics like the Holy Face of Manoppello in Italy. However, Pinna nobilis populations have dwindled due to marine pollution, leading to an EU ban on harvesting and rendering the craft nearly extinct, with production limited to a handful of artisans.
To address this, the POSTECH team turned to Atrina pectinata, whose threads mimic the original in physical and chemical properties. They developed a processing method to create fabric that matches the ancient material's appearance. Beyond recreation, the study revealed the secret to sea silk's timeless color: structural coloration from nanoscale 'photonin' protein spheres. These layered proteins reflect light like butterfly wings or soap bubbles, producing the glow without dyes, which explains its resistance to fading over centuries. The color's vibrancy increases with the proteins' orderly arrangement.
This innovation repurposes discarded byssus threads from marine farming, cutting waste and fostering eco-friendly luxury textiles with historical significance. As Professor Dong Soo Hwang stated, 'Structurally colored textiles are inherently resistant to fading. Our technology enables long-lasting color without the use of dyes or metals, opening new possibilities for sustainable fashion and advanced materials.' The findings appeared in Advanced Materials in 2025.