Superwash yarns, especially superwash merino, are some of the most loved yarns in the knitting world. They are as seductive as an ice cream van jingling its song up your street on a hot day. I know my stash is stuffed with colorful superwash yarns of all sizes.

Why do we love them so much? That’s easy: washability (duh), softness and color.

Superwash yarns (mainly merino, but other superwash yarns, too) have properties that make a knitted fabric that is a little different from their non-superwash sisters. I’m talking less about sock yarns and sock knitting, and more about using superwash yarns for knitting garments or accessories.

Have you noticed that superwash yarns are grand and glorious, but they don’t really act the same as non-superwash yarns?

I’m in no way saying that superwash yarns are bad, wrong or anything negative, but they have a feel and behavior very particular to themselves. I’ve knit all kinds of things out of superwash yarn in a variety of gauges, and the knitting and the resulting fabric are never quite what I expect.

What makes superwash yarns both super and washable is the removal and/or suppression of the tiny scales that cover each individual fiber. The most common way to create a superwash yarn is to remove the scales and then coat the yarn to smooth it (more about this process in an upcoming post). These altered scales can make the yarn and its resulting fabric a little tricky.

I’ve seen knitters blame themselves for superwash knitting that goes a little awry, but as I always say: it’s not you; it’s the yarn.

It’s always the yarn.

Pictured above are three superwash merino yarns, from the top: Neighborhood Fiber Company Studio Sock (shade: Hampden), Malabrigo Rios (shade: Apple Green), and Fiberstory Core Bulky (shade: Flutter).

When I study a yarn, I look and touch first, then I swatch. Let’s go!

In the MDK Shop Raíz by Amores Yarn Studio is dyed just for us in a palette of harmonious contrasts. It's perfect for your favorite shawl pattern. Amores Raíz

Look

Superwash yarn is extra smooth, and the color is so intense that it looks like a cartoon idea of yarn.

Color is always what always brings me to superwash yarn. The color of superwash yarn can be concentrated and much brighter than the same color on a non-superwash yarn of the same breed/blend. Why? Because more dye makes a deeper color, and altering the scales on the fiber allows for increased absorption of dye.

Touch

Superwash yarn feels delightful; it’s smooth and supple. It feels dense and squishy. It feels heavy for merino yarn, but it’s a languorous heft. Having some or all of the scales altered decreases the elasticity a bit, so it’s got extra drape. Coating the yarn, like putting pomade on your hair, compresses and smoothes the fibers, making the yarn dense and even. Rarely does fresh superwash yarn look fuzzy.

Swatch

Up to this point, after looking and touching, I am deeply in love with superwash yarn, but what happens in the swatching and knitting is what makes me a cautious superwash lover.

Fiddling with the scales on the fibers in the superwash process affects how the fiber behaves. The scales on fiber are what help yarns hold together when they are spun and plied. Remove and smooth the scales, and the fibers have no natural way to grip each other. They are twisted around each other, but not locked together. Imagine a game of Red Rover where the defending team stands shoulder to shoulder, but doesn’t hold hands. The defensive line is not as structurally sound.

Since some of the natural structure is missing from the yarn, it’s splitty, less elastic, and it compresses easily. No one will be surprised that my gauge is different with superwash yarn. The yarn compresses since some of the structure is missing. I have to go down a needle size to get the same gauge I get with a similar sized non-superwash yarn that knits to the same gauge.

Because the fibers aren’t hanging on to each other, superwash yarns work best if knit tightly to help give them some of the structure that they are missing. (This is why superwash yarns are great for socks.)

For me this shows up most when superwash yarns are wet.

My friend in the photo is holding two damp swatches. The one on the right is knit to the gauge suggested by the ballband (4.5 stitches to the inch) and the one on the left just slightly looser (4.25 stitches to the inch).

When the yarn hits the water all of my beautiful knitting goes limp like a tired toddler asked to pick up toys (shrieking, optional). When it’s knit looser than suggested gauge it really doesn’t hold the shape of the stitches well, dry or wet. This tells me not to stray looser than the suggested gauge. (Superwash yarns therefore are not candidates for gauge shifting.)

I’ve learned to be extra careful wet blocking superwash garments, and I expect them to take a little longer to dry because of the density of the yarn.

The hand of the fabric and stitch definition are often the spots where love either blooms or dies on the vine for the knitter considering superwash yarn for projects that are not socks.

The hand is how a knitted fabric feels. Is it soft or rough, stiff or drapey?

If you are a lace knitter, particularly with a penchant for lace shawls, the smooth heaviness of superwash gives your piece swing. The lack of elasticity allows your block to hold all of those YOs open. It brings a languid drape to your shawl, like reading and swinging in a hammock on a summer afternoon.

If you are looking for a cable that stands at attention, superwash yarns can be a little, um, flaccid.

The cable swatch in the photo is knit with bulky yarn, with many plies, at the gauge suggested by the ballband. If the yarn were not superwash it would have almost no bend, instead it hangs there like Droopy Dog.

That is one flat cable. There is nothing approaching crisp stitch definition unless it is knit tightly. If you do knit tighter, that further compresses the yarn and makes the fabric heavier. Asking a superwash yarn to have superior stitch definition is like trying to thread cooked angel hair pasta through the eye of a needle.

But the Color!

Superwash yarns remind me of my neighbor’s cat: beautiful, and when you pet her in exactly the right place she happily purrs. If, however, I suggest to her I’d like to pet her in a way that works for many other cats I know, but not her, I find teeth and claws attached to my hand.

The takeaway: Come for the color and softness, but arm yourself with a little knowledge about how this yarn likes to be knit.

(Because I know you want to know, the yarn in the last photo is Lichen and Lace 4-ply superwash merino worsted, and the color is Sweet Potato.)