Choosing the Right Yarn: Felting

Sometimes all it takes to get us knitters to plunk down a chunk o’ change for a ball of yarn is a blend of pretty colors and a yarn that feels good against our cheek. Sometimes, however, you need a yarn with certain qualities: you’re sensitive to wool, you want to make a felted project, you want something washable. How do you know if the yarn you are holding in your hand is the RIGHT yarn for your felting yarn project?

Ah, now. This is something I learned about from my spinning classes, folks. So all you out there who were wondering why the heck I was going on and on about spinning last week. There is a method to my madness. Over the next few months, I’ll have some posts about choosing yarn, the RIGHT yarn, for your knitting—and I will share some of the knowledge about felting yarn I learned whilst learning to spin.

In today’s post, we’ll talk about choosing yarn for a felting yarn project—one you knit first, then toss into the washer with the intention of shrinking it and matting it up into a solid-ish, fuzzy-ish fabric.

On Choosing and Felting Yarn:

How do you know which yarn will felt?

If you are making a felted project, the first thing you need to ask is: did the fiber come from an animal? If it did, then it might felt. (Notice: I said “might.”) Next, look at the label and ask: Is it ALL from an animal? Any non-animal fibers in your yarn will either cause it to not felt at all, or cause the felting to be a bit less consistent and “felt-y” than you probably want it to be.

Why does yarn-from-an-animal felt?

Sheep and other animal fibers are scaly—picture a fish’s scales covering each fiber. When you dunk wool into hot water and swish it around, these scales open up, sort of like lots of little umbrellas opening up all along the length of the fiber. When they open up, the scales catch onto nearby scales and grab on. The more fibers you have, and the more you rub the fibers around, the more scales there are to catch onto each other. The fibers get all tangled up, and more scales grab tight, until you have felt. Learn more about wool scales and look at fiber on the microscopic level in the article “The Itch Factor” in Spin Off Summer 2015.

Do all animal fibers felt?

I would have to say “to varying degrees” and “eventually.” A disclaimer is in order: I am by no means a felting expert, and I haven’t read every single book on the subject. So if you know more than I do, please chime in here!

Some wools have smaller scales, some have larger scales. Some have “smoother” scales, some coarser. All of those little details will affect the degree to which the wool felts. Also: The way in which a particular fiber is processed and dyed affects felting. Did you know that a white yarn may felt differently than a colored yarn of the same type and brand? This is because the dyes can smooth down, or raise up, the little scales on the colored yarns. White yarns may be bleached, which affects the yarn differently. Naturally colored yarns may not be dyed or bleached at all.

Some yarns are specially treated with a substance that smooths down the scales. These yarns are called “superwash” or “machine washable” wools, meaning you can wash them in a washing machine and they won’t felt. However, over time, with wear and a lot of machine agitation, the special fiber treatment may rub off, and your socks may start felting.

So: No scales, no felt. Sheep’s wool is not the only fiber with scales, so it is not the only animal fiber that felts. Alpaca will felt. Llama will felt. Each animal’s fiber is slightly different, however, so (you’re going to hate me for this…here it comes…) swatch carefully, including felting your swatch, before deciding whether the yarn you want to use is the RIGHT yarn. Learn more about yarns and fibers in this list of the 15 Things You Should Really Know About Yarn!

Really? ALL animal fibers?

The ONE exception to the Animal Fibers Are Candidates For Felting Yarn rule is silk. Silk comes from silkworms, and I would argue that worms are not animals, they are worms, thus: bugs. Silk is not worm hair. Silk is extruded from the worm; silk starts out as a liquid. (Ahem. Use your brains, here, folks: “extruded” plus “liquid” equals…oh yes. That’s what silk is. Hardened Bug Extrusion. Very pretty and wonderful hardened bug extrusion, it is, too.)

Bug extrusion hath no scales, therefore, silk won’t felt.

Have you learned something about felting yarns that felt and won’t felt? Leave a comment and help the rest of us learn from your experiences. And to learn more about felting your knits, check out the book Felted Knits and the magazine Felted.

—Sandi Wiseheart

Featured Image: “Circles Table Runner & Placemat by Maggie Pace, Felt Forward. Photo by Joe Coca