"Silk 143" generally refers to a specific 143 kDa recombinant protein used in biomedical research for studying liquid-liquid phase separation, as detailed in scientific reports. Alternatively, it may refer to a "Douppioni Silk 143" fabric code or "Planet Earth Silk 143" embroidery thread, rather than a single software download. For technical data on the protein, see the report on ScienceDirect .