the back of 260lines hand-made chinese silk carpet

This picture shows the back of 260 lines hand-made Chinese silk carpet zz206309. 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.