This Persian runner has a wool foundation and a wool pile. It has a standard 110 knots per square inch.
 
This stunning Shiraz rug is a great example of Persian tribal pieces. Weaved by nomadic tribal people near the city of Shiraz in south west Iran using soft hand spun wool and vegetable dyes. The geometric patterns are also inspired by traditional nomadic designs. Though tribal rugs such as this may not have as high a knot density as city pieces, they are nevertheless hard wearing, good quality pieces that bring a warmth and character of their own into any setting.