Knot Count
A knot per square inch (KPSI) is a measurement of the density of knots in a hand-knotted rug and is a general indicator of its quality and durability. Knot count can, however, vary substantially depending on many other factors (such as style, origin, etc.). So this measurement is just one aspect to take into account when assessing a rug.
How do you measure it?
Turn a hand-knotted rug over and count the individual knots you can see running vertically for 1’’ and then horizontally for 1’’. Multiplying these two figures together will give you the overall KPSI.
Compare KPSI Qualities
Each knot is in comparison to a pixel; the more pixels in a given area, the clearer the image. It applies to rugs as well.
More knots compressed into a square inch not just increase the intricacy and clarity of the design, it increases the durability of the rug as the knots are closely packed.
To accommodate for more knots, finer material may also be used like silk or thinner yarn, which increase the quality of the rug by the material used to create it. Higher KPSI also means more time on the loom, ranging from 5 to 12 months to completion.
The KPSI quality is displayed as vertical knots x horizontal knots e.g 8x8 – pronounced ‘eight eight’ quality.
Persian Knot (Asymmetrical)
The knot is made by wrapping the yarn once around the warp and then passed under neighbouring warp strand. This knot type is used in creating hand-knotted rugs. Used in Iran, India, Turkey, Egypt and China.
Turkish Knot (Symmetrical)
The knot is made by passing the yarn over two neighboring warp strands. Both ends of yarn come out between both warps. Used in Turkey, Iran and the Caucasus.
Tibetan Knot
A weaving technique acquired from Tibet. Yarn is looped around two warps and around a rod. After the rod is covered with loops, a cut is made to form pile and remove the rod.