Knots per square Inch (KPSI)

The second factor in determining the quality of rugs, specifically hand-knotted, is in knots per square inch.

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.




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.

Hand-Knotted Rugs KPSI Example
Quality5x8
(150x240 cm)
8x10
(240x300 cm)
9x12
(270x360 cm)
10x14
(300x420 cm)
8x8
(64)
368.640
(knots)
737.280
(knots)
995.328
(knots)
1.290.240
(knots)
10x14
(140)
806.400
(knots)
1.612.800
(knots)
2.177.280
(knots)
2.822.400
(knots)
14x14
(196)
1.128.960
(knots)
2.257.920
(knots)
3.048.198
(knots)
3.951.360
(knots)