Real silk is produced as the cocoon covering of the silkworm, the pupal form of the Asian or mulberry silk moth, bombyx mori. The cocoon is spun by the silk moth caterpillar of a single silk fiber that can be up to several thousand feet in length. To harvest the silk, completed cocoons are boiled or heated to kill the silkworms, then laboriously unwound into single fibers which are plied together and spun into thread or silk yarn.
Natural silk is a fibrous protein composed of a number of amino acids: glycine (44.5%), alanine (29.3%), serine (12.1%), valine (2.2%), tyrosine (5.2%), glutamic acid (1%), others less than 1% each. Chemically, natural silk is C15H23O6N5 (we give the formula in case you want to whip up a batch of your own). Silk is extremely high in tensile strength, exceeding that of nylon. It has been estimated that if a single silk fiber with the diameter of a pencil could be produced, the fiber could lift a 747 aircraft (who figures these things out, anyway?). Silk is used to make Oriental rugs because dyed silk is a fiber with rich, saturated colors, and a distinctive, almost translucent luster.
Dr. Khosrow Sobhe (Dr. Kay)
Certified Rug Specialist (CRS)