the back of 260lines hand-knotted oriental silk rug

This picture shows the back of 260 lines hand-made oriental silk carpet zz185279. 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 (470KPI).
For this quality hand-made silk rug, each person can make
around 2.25 square feet per month.