Why Does Wool Felt?
Recently I was reading various online sites about felting and about making felted purses and I was amazed to see a felted bay designer explaining that wool felts because it has a spiral structure and the coils get tangled and that makes felt. This is an incorrect explanation of why wool felts, so I decided I should write a little about it. As someone who has taught spinning and fiber classes since 1970 I have always explained felting this way: Wool fibers have tiny microscopic scales along their surface. Some types of wool have larger scales than others. The types of wools that are coarser and smoother and have the highest sheen to them (such as Lincoln, Leicester, Wensleydale) have larger scales and reflect more light off their surface leading to the sheen. Finer wools (of which Merino is the main example) have much, much smaller scales and do not reflect light and have a more “matt” look to the surface of the yarn or finished knitting. When wool fibers are shocked by temperature and
