The fineness of the wool is stated in the micron. Micron is the thickness of the wool fiber in diameter. 1 Micron = 1 thousandths of a millimeter = my.
If it is a low micron number, it is fine wool and if it is a high number, the wool is coarser.
It is often said that scratch-free wool has a micron that is 22 microns or lower. Coarser wool itches because it is not soft enough to bend in contact with the skin. Merino wool Ulvang uses in our collections is normally 16-19.5 microns. In comparison, Norwegian wool, which is coarser, has a coarseness of approx. 28 microns and up. Garments with a low micron are well suited as the first layer directly against the body, but products with a coarser micron are better suited in sweaters. In all our socks we also use wool with a slightly higher micron as we are not so sensitive to itching on the legs. Higher microns also normally provide more durable products.