Material of the Month: Wool

Today, I am starting a new feature here on the blog: material of the month. Each month, I will try to talk about some of the features and advantages (as well as the downsides) of a different material I have worked with. I guess we'll see how long I can keep it up until I run out of materials.

So, to start: wool.

Wool is a natural fiber (naturally) and has been used since ancient times to make cloth and textiles. Traditionally, wool was a warm but rather rough material, good for outer-wear like sweaters and coats, or hard-wearing textiles like rugs and tapestries.

However, starting with Merino sheep in the 18th Century, breeds with softer wool have been developed that produce wool without that prickly feeling. When the breed was first developed by the Spanish, Merino sheep were highly prized and nearly impossible to get if you weren't royalty - historical novel writers take note: soft wool was not really a thing that average people had access to.

Today, of course, merino wool is quite common, and is usually the only breed that will be identified by name if you are buying wool yarn. It is very soft and squishy, but knitters beware: it lacks the strength of other types of wool, and should be avoided when making socks, pants, rugs, or anything else that will take a lot of wear.

I will try to talk about other specific breeds in later posts, but today we are talking about wool in general.

Unlike cotton or linen, wool has a natural elasticity. First, because the individual fibers will stretch, and second, because most wool is a bit kinky or curly, and that will translate into the yarn. This stretchiness makes it easy to knit or crochet with, and is easy on the wrists.

Two locks of fine wool

Wool also has a natural ability to "grip" other wool, due to its texture at the microscopic level. This ability is most obvious when you felt or full it: the fibers interlock so that they can't be easily separated. But it also comes into play when spinning, as it doesn't take much to make the wool adhere to the leader or to make a join. This also means that, unlike some other fibers (cotton, alpaca) wool fabric will not "grow" over time under its own weight. Instead, changes in temperature and humidity will gradually, lightly felt the wool so that it keeps its shape indefinitely.

I don't really do felting, but here is a lopi hat, lightly fulled in a dryer so that it loses stitch definition.

To summarize: warmth, elasticity, and ability to grip and felt are some of the reasons why wool is the go-to material for knitters and crocheters (I'm ignoring synthetics, for now). It also takes dye very well, and most modern sheep are white, making it particularly easy to get yarn in whatever shade you want. Wool is also pretty inexpensive (at least in the U.S.), rivaled only by acrylic yarns.

All that said, there are some well-known disadvantages to wool as well.  First, as I alluded to above, there is a trade-off between softness and strength. In order for wool to be strong and take a lot of wear, it needs to have thicker fibers, and those tend to be less soft and more prickly. Second, it is hard to wash. That amazing ability to felt means that hot water and agitation will cause your garments to... shrink and felt. You can buy "super-wash" wool that does not have this problem (due to chemical treatments of various kinds) but it will not have that gripping advantage, and won't block very well.

Finally, wool's warmth can be a disadvantage in the summer or in warmer climates. It does wick moisture well though, so you can sweat a lot in wool without it even feeling wet if you wanted to go hiking in wool socks. That wicking can also be a disadvantage though - wet wool can hold a lot of water, making it very heavy to wear in the rain, and it will take forever to dry.