Bradford system

The Bradford system (also known as the English Worsted Yarn Count System or spinning count or Bradford count) is a way to assess the quality of wool.

To measure the fineness of sheep wool fiber before microscopes and lasers were so used, English wool handlers in the city of Bradford described wool by estimating (with experienced eyes) how many 560-yard hanks of single strand yarn could be made by a good spinner from a pound of "top." (Top is cleaned combed wool with the fibers all parallel) The finer the average diameter of a single wool fiber, the more hanks could be spun. From a pound of "64s," for example, sixty-four such hanks could be made (more than 20 miles!). From the finest wools, more than 80 hanks could be spun; from the strongest, perhaps 36 or fewer. Using ranges denoted by the stronger end (that is “44s” ran up to “46s”) wool lots were classified and prices derived.