Martine M. White, ASA, AAA
Oriental rugs are hand-made works of art. Woven on looms, both village and city rugs are unique in their design, knot and color palette. As an appraiser of Oriental rugs, I am often placed in an awkward position in that I have to inform my client that the rug they thought was authentic silk is actually something other than that– in most cases, it’s mercerized cotton.
Silk fiber is produced and harvested from the cocoon of the silkworm, whereas mercerized cotton, although natural, or man-made rayon, another substitute, is a manufactured product. While rugs made with non-silk fibers may initially have a beautiful, soft texture and sheen, they are not as resilient to foot traffic nor will they return from being cleaned with that alluring sheen, texture or appearance. With use and subsequent wear, the pile of a rug made with a mercerized cotton fiber will actually lay flat, clump together and lose its vibrancy. Unlike natural silk, mercerized cotton or rayon will start to accumulate dirt and take on a soiled look, even though it may have just been cleaned.
So how do you determine if you have an authentic silk rug? One method for identifying silk is to clip off a loose fiber from the rug and burn it. When silk fiber burns, it will curl up and leave a hard, black ash and skeleton of the fiber. This natural fiber will also smell like burning hair. Conversely, when mercerized cotton is burned it will turn into black ash that will be loose and flakey. Ignited mercerized cotton fiber will also smell more like burning paper. If the burn test seems extreme, you can also rub the fibers with your finger to determine the difference. Silk will stay cool to the touch when you rub it, and mercerized cotton will feel warm. That noted, this is a difficult technique for discerning a difference reliably. Also, don’t be fooled by a silk fringe, as many of these faux-silk rugs have the fringes sewn on to deceive the eye. The fringe in a hand-woven rug is always the extension of the warp.
Beyond the techniques noted above for identifying whether your rug is silk or not, the best advice is to rely on the expertise of an appraiser or an experienced, trusted rug dealer who is apt to have silk rugs on hand for comparison – which is the best way to tell the difference!