Does Yarn Get Softer After Washing?

Why washing changes wool at all

Three separate things happen the first time a wool fabric gets wet, and they all push the same way.

1. The twist relaxes. Yarn is spun under tension and holds that tension in the ball. Water lets the plies settle to where they want to sit, and a relaxed yarn is a softer yarn.
2. The fibers bloom. Wool fiber takes up water, swells, and the individual fibers migrate very slightly toward each other. The fabric closes up, the stitches even out, and the surface changes from distinct strands to a continuous cloth. Knitters call this blooming, and it is the single biggest change.
3. The spinning oils come off. Yarn is processed with lubricants so it runs through machinery - more on a cone than on a ball, but present on both. Those residues are part of what you are feeling when a new skein feels slightly waxy or stiff.

How much to expect, by fiber

The test to run before you buy ten skeins

This is the useful part. A yarn's hand in the ball is not its hand as fabric, and a lot of good yarn gets rejected in a shop for failing a test it was never going to pass.

1. Buy one skein. Not the sweater quantity.
2. Knit a swatch large enough to drape - at least 6 inches square. A 2-inch square tells you nothing about how a fabric feels on a neck.
3. Wash it the way you will wash the garment. Cool water, a wool wash, twenty minutes, squeeze out, dry flat. Not a quick rinse.
4. Hold it against your neck when it is dry, not against your hands. Wrists and fingers do not report prickle the way a neck does.
5. Then decide. If it is still scratchy after that, it will always be scratchy and you should buy something else. Knitting gauge and swatching covers doing this properly, and you get your gauge for free.

What softening does not fix

There is a limit, and it is set by the fiber's diameter rather than by anything you can do in a sink.

Prickle is mechanical: coarse fiber ends sticking out of the fabric are stiff enough not to bend against skin, and that is registered as a sharp sensation. Washing lets more of those ends lie down, which is why a bloomed fabric is more comfortable. It does not make the fibers thinner. A genuinely coarse wool will still be a coarse wool after ten washes, and if the problem is a fiber sensitivity rather than prickle, softening is irrelevant. What makes yarn itchy works through the distinction.

Things people try that do not work

• Hair conditioner on wool. It coats the fiber and leaves residue; the effect is temporary and it attracts dirt. A proper wool wash does the job without the film.
• Fabric softener on acrylic. Acrylic is not absorbing anything. You are putting a coating on a plastic filament.
• A hot wash to 'speed it up'. On untreated wool that is how you felt a garment rather than soften it.
• Tumble drying untreated wool. Heat plus agitation is the felting recipe exactly.
• Waiting for acrylic to break in. What softens over time in an acrylic garment is the pilled surface fuzz, not the fiber - see why yarn pills.

The practical upshot

If you are standing in a shop with a wool or cotton skein that feels stiffer than you hoped, buy one and swatch it. The odds are good that it improves, and wool improves the most. If you are holding an acrylic that feels scratchy, put it back - what you feel is what you will own. And if you are upgrading away from acrylic in general, upgrading from acrylic is the page for that decision.