Sofsilk silk sutures are nonabsorbable, sterile, non-mutagenic surgical sutures composed of natural proteinaceous silk fibers called fibroin. This protein is derived from the domesticated silkworm species Bombyx mori of the family bombycidae. The silk fibers are treated to remove the naturally-occurring sericin gum and braided to produce Sofsilk surgical silk sutures. The braided sutures are available coated uniformly with either silicone or a special wax mixture to reduce capillarity and to increase surface lubricity which enhances handling characteristics, ease of passage through tissue, and knot run-down properties. Sofsilk sutures are available white or colored black with Logwood extract. Sterile Nonabsorbable Suture. Sofsilk sutures are for use in general soft tissue approximation and/or ligation, including use in cardiovascular, ophthalmic, microsurgery, and neurological surgery. Wax coating: Smooth, mutiple pass rundown, minimizes breakage.