Wool is warm and wonderful, but it has enough varieties that if you’re new to knitting or sewing, you might begin to wonder if wool is actually a synthetic fibre as opposed to natural. Wool itself is natural, but it can be modified and combined with synthetic materials. It is always best if you can find wool yarn where materials are clearly listed.
What Wool Is
Wool is the hair or fibre from the fleece or pelt of animals such as sheep. Wool itself is not synthetic. It does go through “processing,” of course, to turn the hairs into skeins of yarn, but the core material is natural. Wool can come from sheep, such as merino wool, or it can come from goats (cashmere or mohair), rabbits (angora), camels (camel hair), or alpaca (alpaca wool). The material that forms the fleece and wool is mainly keratin; when freshly shorn from sheep, the hair is covered with a greasy substance (fittingly called wool grease) that is processed to make lanolin.
The word “wool” brings to mind its most common form: a tangled heap of white fleece on a sheep. That image gave rise to “wool” or “woolly” being used to describe other materials that had a similar appearance, such as steel wool, the mass of metal fibres you use to scour sinks. Obviously, steel wool is not the same material as wool from animals; it just has a tangled appearance.
Why Some Wool Is Washable
Wool is usually not something you can wash in a machine unless you’re trying to “felt” fabric to get a particular (and permanent) change in look and feel. Otherwise, you have to dry clean or hand wash wool items. This annoyance was mitigated somewhat with the introduction of “washable wool,” which allowed you to wash the item as if it were made of cotton or polyester. Washable wool is basically natural wool, but it’s been treated with chemicals to make it machine-washable. In fact, it’s somewhat controversial as the chemical treatment process isn’t that environmentally friendly.
The chemicals act as a smoothing layer that protects the natural surface of the wool from the heat and moisture of the washing machine. That leaves the fibres in their natural state in terms of appearance after an agitated machine wash, so the “felting” never happens.
Some companies have devised a way to make washable wool that is less harsh environmentally because the process uses materials like air and even electricity instead of chemicals. You’ll also find people who consider washable wool a synthetic fiber because of the inclusion of those chemicals.
Like most fibres, wool can be blended with other fibres, some of which are synthetic. If you see labels for fabric or yarn that are wool-blend, for example, you’re looking at something that isn’t completely wool. So, you could have natural wool combined with synthetic polyester. That doesn’t make the wool a synthetic fiber, but it does make the fabric or yarn partially synthetic (and thus synthetic as a whole if you’re deliberately trying to find natural fibres).
Wool blends do offer some benefits. While they are not as warm as pure wool, they can be softer, something that is a relief for people with sensitive skin. These blends can also be easier to clean and be cheaper as well, especially if the wool is an expensive type, such as cashmere.
Wool blends are also popular for hiking clothes and other garments that face a lot of dirt. No one really wants to come home from a backpacking trip only to spend hours handwashing all their hiking gear; wool blends allow more of these garments to be machine washed.
Is wool a synthetic fiber? Wool itself, as the hair from the pelt of an animal, is a natural fibre and isn’t synthetic. It can be treated with chemicals, which in some people’s books makes it at least partially synthetic, if not fully synthetic. Blends may be all-natural, such as a wool and silk blend, or partially synthetic, such as a wool and polyester blend. Check labels for materials if you have a specific preference.