What Pilling on a Sweater Means, and How to Fix It
Those little fabric balls on a sweater’s surface are called pilling, and they form when short, loose fibers rub together and tangle into knots instead of shedding away cleanly. It’s a sign of friction, not necessarily a sign of a cheap sweater — even expensive knitwear pills if it rubs against a bag strap or seatbelt often enough.
Why Some Sweaters Pill and Others Don’t
Pilling comes down to fiber length and how tightly a yarn is spun. Short-staple fibers, common in cheaper acrylic and some cotton blends, work loose from the yarn easily and tangle on the surface. Long-staple fibers, like those in higher-grade merino or cashmere, are less prone to it because there’s less loose fiber to begin with — though loosely spun yarn made from good fiber can still pill if the twist isn’t tight enough to hold it in place.
Where the pilling shows up is a clue, too. Pilling under the arms, at the sides where a bag rubs, or across the lower back where a seatbelt sits is friction damage. Pilling spread evenly across the whole sweater usually points to the fiber or yarn construction itself, not how you’re wearing it.
Removing It Without Damaging the Knit
A fabric shaver or pilling comb removes existing pills without pulling on the knit the way scissors or a disposable razor can. Work in short, light strokes in one direction, keeping the fabric taut with your other hand, and stop as soon as the pills are gone rather than continuing to shave the surface. Going over the same spot repeatedly thins the fabric and can eventually wear a hole where the pilling was worst. A sweater comb, the older manual tool with fine teeth, does the same job more slowly but with less risk of catching and snagging a loose thread than a motorized shaver can.
Reducing How Often It Happens
Turning a sweater inside out before washing keeps the friction of the wash cycle against the inside of the garment instead of the visible surface. Hand washing or a gentle cycle in a mesh bag reduces the tumbling that causes pilling in the first place, and skipping the dryer avoids the heat and friction combination that’s especially hard on wool. Rotating sweaters instead of wearing the same one two days in a row also spreads out the wear that causes pilling under the arms and at the sides. It’s also normal for a new sweater to pill more in its first few wears than it ever will again — that initial round is usually just the short, loose fibers left over from manufacturing working their way out, and it tends to slow down once they’re gone.
Pilling resistance is something the textile industry tests for directly — the American Association of Textile Chemists and Colorists maintains standardized abrasion tests that manufacturers use to rate how a fabric will hold up. For your own closet, the practical version of that test is simpler: how you store a sweater between seasons and whether you know how wool behaves differently from other fibers will tell you more about pilling risk than the price tag did.
