In 1968, the United States Department of Agriculture issued official standards (for the U.S. only, not applicable worldwide) which assigned ranges of average fibre diameter (AFD) and maximum standard deviation to each of the Bradford counts.
In 1968, the United States Department of Agriculture issued formal guidelines (for the U.S. only, not applicable globally) which assigned ranges of average fibre diameter (AFD) and maximum standard deviation to each of the Bradford counts.