If you are a crafter, you have probably worked with wool in one way or another. Wool is available as yarn, fabric, felt, and as the fibre itself. We spin it, knit it, crochet it, weave it, sew it, or felt it. Wool is everywhere in the crafting world.
Some people use the word wool to describe fibre from all fibre-producing animals, but I am going to use it here to only describe fibre from sheep. Even then, wool is a very broad term when applied to the fleeces of over 250 registered sheep breeds, dozens of recognized but un-registered breeds, and dozens more regional and farm-specific variations made to each of those breeds. Each sheep breed produces a distinct style of wool, but there are variations within the breeds and more variations within each individual fleece. However, there are certain characteristics that we can assume exist in every type of wool.


While not to scale or overly detailed, this drawing represents a cross-section of a wool fibre. The centre core, the medulla, varies widely in size from breed to breed—from relatively large in coarse long wools to so small it is virtually non-existent in some very fine wools. The cortex layer also varies in size and determines the fineness and crimp of the wool. The epidermis, now more commonly called the cuticle, is the layer of tiny scales on the surface of the fibre that help the fibres hold together in a spun yarn. (Illustration by Michelle Boyd, originally drawn as part of her Master Spinner Program homework and based in part on an illustration from the book In Sheep’s Clothing by Nola Fournier and Jane Fournier)
Find more detailed information on the structure of wool fibres:
woolmark.com/fibre/
woolwise.com/wp-content/uploads/2017/07/WOOl-472-572-14-T-02.pdf [PDF]
All photos by Michelle Boyd.