This is the back of the carpet and in order to calculate the knot density, I need to count how many knots there are in an inch in this direction and then in an inch in this direction. Because this carpet is very fine, I can only see one bump at the back per knot So I'm going to count them ... one, two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen, fifteen, sixteen. So there are 16 knots in one inch in that direction. And in this direction there are one, two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen. Fourteen multiplied by sixteen is 224. So there are 224 knots in a square inch in this carpet. This is quite a fine carpet, but for a really, really fine carpet
you may get more than one thousand knots per square inch.