Gorgeous antique Caucasian Soumak rug from late 1800s. Soumak rugs are made from a unique construction technique that produces a flat-weave rug that is very strong and exceptionally durable. Unlike kilims, these rugs are not reversible because non-clipped yarns are left on the back. However, they are also stronger than kilims. Thicker than a kilim carpet, it is accomplished by looping the yarn horizontally around successive pairs of warps in between passes of over-under wefting. When compressed vertically with a weaver’s comb, the resultant texture looks like cabling rising slightly from the surface of the rug. These rugs are very finely woven and feature richly detailed geometric motifs. brocading or flat-woven pile.