the back of 260lines hand-knotted persian silk rug

This picture shows the back of 260 lines hand-knotted Nain design silk carpet z18785. The knots are very clear and dense. There are 22 lines
of knots per inch and there are 470real tied double knots per square inch(knots count is 470KPI).
For this quality hand-knotted silk rug,
each person can make around 2.25 square feet per month.