Kashan rugs are high-quality, many incorporating silk into their designs. The foundation tends to be cotton however some of the finest examples may be pure silk. The wool should be soft and the pile tightly knotted. The knot count (KPSI) can range from 100 to over 800 per square inch for the most majestic examples. The majority of Kashan's have a similar design with a central medallion and Persian floral motifs forming the pattern, however as with most regions designs may vary.