Knot density
From Wikipedia, the free encyclopedia
Knot density is a traditional measure for quality of handmade carpets. It refers, quite simply, to the number of knots per unit of surface area - typically either per square inch or per square centimeter.
For two carpets of the same age and similar design, the one with the higher number of knots will be the more valuable. With more than 30 knots per square centimeter (1 sq cm = approx. 0.155 square inch), the carpet pattern will have less pixelation. The carpet's surface will also feel more solid and will give better protection against aging.
A Persian carpet with fewer than 30 knots per sq cm is generally considered an average to low-quality carpet, while over 50 indicates a fine piece of work.
Hand-tying of knots is a very labour-intensive task. An average weaver can tie almost 10,000 knots per day. More difficult patterns with an above-average knot density can only be woven by a skilful weaver, thus increasing the production costs even more.
