Natural silk, Artificial silk in Rugs by Image Carpets

Natural silk, Artificial silk and the rugs made from them

Silk rugs are the height of luxury and opulence, made as much for display as for daily use. Natural or real silk is made by unwinding the cocoons of the silk worm (Bombyx mori). To produce 1 KG (2.2pounds) of silk yarn, 104 kg (230 pounds) of mulberry leaves must be consumed by 3000 silk worms.
Thus a rug weighing 10 kg., assuming an all silk foundation, and considering that 2/3 of the silk knotting yarn is lost in the surface clipping, 30 kg. of silk, the work of 90000 busy silk worms is required. Combine this with the laborious processes of the unwinding the cocoons, spinning the yarn and the dyeing it, the very fine knotting (300,400,500 or more knots per square inch) and the cost of a detailed cartoon for the weavers to follow, and one can easily see that a quality silk ought to be expensive.
Beware, therefore, of cheap imitations! In Turkey, India and Pakistan the unwary can be trapped into buying a “silk” rug not made from real silk, but usually of mercerized cotton instead. Cotton, a plant fiber composed of cellulose not protein, is mercerized ( a process developed in the 19 th century) by treating the yarn with caustic soda when it is stretched under tension. This imparts a glossy surface finish which is further enhanced by calendaring it, e.g. passing it through heated rollers. But the cotton does not change chemical composition and it still does not have the high tensile strength or iridescent colors of dyed silk.
The simplest, most direct way distinguish them is a simple burning test. Select a knot or bit of fringe, any part asserted to be silk, and apply a lighted match. Cotton, being cellulose, like trees and paper burns to a grey, powdery ash, while silk composed of protein, shrivels up into a black ball with the odor of burning hair (another protein fiber). This test is always definitive; if one is not sure of the result, repeat it on another bit of the suspect rug.
Silk rugs are primarily a non-functional decoration and do not wear well under shoe traffic because the silk fibers lack the elasticity of wool, the ideal carpet fiber. They are for the wall or as a throw over furniture. Silk rugs must be in excellent condition with the full pile to have a real value. A worn silk, unless it has a substantial documentary, aesthetic or period significance, should be avoided.
To see more silk rugs please see www.imagecarpets.com

Comments: