What is KPSI how to count KPSI on Rugs and Carpets

http://www.rugrag.com/post/What-is-KPSI–Its-not-always-the-Knot-that-Counts!.aspx KPSI is a quality measure used to determine knot density in Oriental Rugs. This video is a “How to” for Quick and easy ways to determine KPSI in Oriental and Persian hand knotted rugs. Use a quarter, and count ’em!