As you begin diving into the world of Merino wool apparel you will quickly see that items are described by the weight of the product. Typically this is discussed as the fabrics micron weight. I actually very casually dropped the “micron” terminology in my last post “The Australian Wool Market“.
Anyone with a little knowledge understands that a micron is a measured unit of length. But, the origins of using the terminology in merino fabrics began out of a necessity to develop a wool grading system. The number of microns, i.e., the measurement of the wool fiber in thousandths of a millimeter, is now used to indicate quality. Fine wool is between 17 and 23 microns. When wool is perceived as itchy, the reason is that there are coarse fibers in the wool, which do not yield to the skin but rather stick in. The finer the fibers, the softer the feel of the textiles. Coarse fibers in excess of 28 microns may itch.
These grades may vary depending on the breed or purpose of the wool but for Merino, here is a typical breakdown. For example:
* <15.5 – Ultrafine Merino
* 15.6-18.5 – Superfine Merino
* 18.6-20 – Fine Merino
* 20.1-23 – Medium Merino
* 23< – Strong Merino
For most apparel that is designed for athletic pursuits you will see a micron range of 17-20 or so. Other companies choose to describe there garments by the weight of the wool. To each their own.
Finally, one other thing to make mention of is that of the world’s finest wool. The world’s finest merino wool was produced initially in 2004 at 11.8 microns and then later upstaged in 2008 with a wool ranking in at 11.4 microns. The company who produced it received a little less than $250K for a full bale. Wow! I guess we won’t be seeing a 11.4 micron base layer anytime soon!