The silk suture is made from braided silk fiber threads (polypeptide chains). Available in uncolored (white) or dyed black with Sulphol Black 1 dye, C.I. 53185, or Hematein Black. The suture material is coated with a blend of wax and/or silicone. It meets all requirements established by the European Pharmacopoeia for non-absorbable sterile sutures. "Silk (Filum Bombycis)" and United States Pharmacopeia (USP). "Non-Absorbable Surgical Suture."