what is the difference between 4 ply and double knitting wool?
The ply of a yarn refers to how many strands of yarn are spun together to make the yarn. ... Typically, 4 ply yarn is equivalent to medium weight yarn, which means that it is possible for double knit yarn to be 4 ply as well. This is not always the case, though, since fibers with thicker thread will create a bulkier yarn.