Whether a Tibetan carpet is made in Tibet, Nepal or India, the common feature is the ‘Senna knot’. This unique technique originated in Tibet and has remained unchanged for centuries. The ‘Senna’ knot is done by using a metal rod, which is placed horizontally against the warp. The yarn is first looped around two warp threads and then looped one more time around the rod. When the weaver has completed one row of knots the loops around the rod are cut to create the pile of the carpet.