Why Do Shirts Pill? And How Do You Stop It?

October 22, 2026 C.B. Shaw

Why do shirts pill? Pilling happens when loose fibers work their way to the surface of the fabric and rub into tiny balls. Wear and washing push the fibers out, friction rolls them up, and any fibers still attached to the fabric hold the ball in place. It is not automatically a sign of a cheap shirt: soft, fine fibers and loose knits pill, and some very expensive fibers pill early. Think of it like a bar fight in a crowded room: everybody's rubbing shoulders, a few loose threads get tangled up, and suddenly there's a ball of trouble in the corner that won't leave. This post explains how it works, which fabrics start the most fights, how labs measure it (with a strange wartime backstory), and what actually clears the room.

Fair warning: the research behind the folk remedies is thinner than you'd think. Where there's a real test, we cite it. Where there are only opinions, we call them opinions and move on.

How a pill forms

Think of a fuzzy sweater as a crowd of tiny threads sticking out of the surface. Every time you move, wash or sit against something, those threads rub. Wikipedia, drawing on a 1998 review in the journal Textile Progress (we didn't open the original), describes four stages: fuzz formation (loose fibers poke out), entanglement (they tangle), growth (they ball up) and wear-off (the ball finally breaks away).

The key detail is what holds the ball on. In wool, the fibers are weak, so pills break off quickly and pilling eases over time. In polyester and other synthetics, the fibers are strong, so the pill stays anchored to the fabric. That's why a polyester shirt can look pilled for ages, while a wool sweater pills early and then calms down. Strong fibers hold a grudge. Weak ones let go.

Who pills the most?

The same sources say pilling is worst on wool, cotton, polyester, nylon and acrylic, while linen and silk pill less. Pilling is more likely with:

Short fibers. More fiber ends poke out.
Loose knits. More room for fibers to escape.
Blends where one fiber is much stronger than the other, because the strong one anchors the pills.

Factories fight it by increasing yarn twist (more twists per inch cuts pilling), singeing the fuzz off, applying polymer coatings, or treating cotton with cellulase enzymes. Our post on cotton vs polyester blends explains why blends behave the way they do, and French terry vs fleece vs waffle knit covers a fabric known for pilling when it's cheap.

The wartime machine that tests it

Labs rate pilling on a scale of 1 to 5, where 5 means no pilling at all. Two ASTM standards (ASTM is a US standards body) cover it: D3512, the Random Tumble Pilling Tester, and D4970, the Martindale Tester. Both rate fabrics against visual standards, and both say right in the document that they are not recommended for acceptance testing because results between labs aren't precise enough. The standards were updated in 2022.

The Martindale story is the surprising part. Two trade articles for the machine's 80th anniversary (2022) say Dr. James Graham Martindale devised it at the Wool Industries Research Association in the UK during World War II. The job was wear-testing fabric impregnated with carbon, meant to protect people from gas attacks. Stanley Dilworth, the association's workshop head, built the first machine in 1942, and the rubbing motion came from a pattern he noticed in a yarn-spinning machine. James Heal built its own version in the 1950s and added an electric counter. So the standard pilling test traces back to a gas-mask-era fabric project, not a shirt problem. (These are trade articles, and the maker has a marketing interest. The two articles agree. Also, the original 1942 purpose was abrasion and wear testing, and we couldn't pin down when the machine was adapted for pilling. The paper trail goes cold there.)

How to remove pills: one hands-on test

We found one hands-on comparison, not a lab study. Gentleman's Gazette (March 2026) tested nine tools on a 100 percent wool sweater and scored them out of 10:

Tool	Score	Notes
Electric fabric shaver	10
Nail file	10
Facial shaver	8
Disposable razor	8	Can cut a hole
Pumice stone	6	Messy
Clothes brush	5
Tweezers or scissors	3
Lint roller or tape	2	Only lifts loose debris
Sandpaper	1

That's one reviewer, one wool sweater, no lab method. Combs weren't in the test, and a reader comment said combs snag. Wikipedia also says shaving removes pills. The takeaway: tape and lint rollers mostly don't work, because they pick up loose fuzz but can't detach the pills. Bringing a lint roller to a pill fight is like bringing a butter knife to a boxing match.

How to prevent them

The one prevention tip with a source behind it is to turn clothes inside out before washing, which Wikipedia lists. Gentle cycles, going easy on the dryer and washing with similar fabrics all make sense given how friction builds pills, and plenty of people swear by them, but nobody has put them through a proper test yet. Take them as good logic, not gospel. For the bigger picture on keeping fabric in good shape, see do heavier T-shirts last longer and how to tell if a T-shirt is good quality.

Does fabric softener stop pilling? The jury is still out. We went looking for an extension or lab answer and found patents and blogs, which is the internet's way of saying nobody knows.

Pilling myths, graded

“Pilling means the shirt is cheap.” False or misleading. Soft, fine, short-fiber fabrics and loose knits pill, and cashmere and merino pill early. Wool pills shed over time.
“Tape or a lint roller removes pills.” Mostly false. It scored 2 out of 10 and only picks up loose fuzz.
“Shaving makes it pill more.” Unproven. No source either way.
“Fabric softener stops pills.” Unproven.
“Once it pills, it will always pill.” Not quite. Wool pills fade as weak fibers break away, while synthetic pills hang on.

Questions people ask

Why do shirts pill?

Loose fibers work to the surface, friction rolls them into balls, and fibers still attached to the fabric hold the balls in place.

Does pilling mean a shirt is low quality?

Not necessarily. Soft, fine, short-fiber fabrics and loose knits pill, and cashmere and merino pill early.

Which fabrics pill the most?

Wool, cotton, polyester, nylon and acrylic, according to Wikipedia. Linen and silk pill less.

Why does polyester pill and not fall off?

Its fibers are strong, so pills stay anchored. In wool, the weak fibers break and the pills fall away.

How do you remove pills from a shirt?

In one hands-on test, an electric fabric shaver and a nail file scored 10 out of 10 on a wool sweater. Tape and lint rollers scored 2.

Does a lint roller remove pilling?

Mostly no. It lifts loose debris but cannot detach pills.

Is it safe to use a razor on pills?

A disposable razor scored 8 out of 10 but can cut a hole, so go carefully.

How do you prevent pilling?

Wash clothes inside out. Gentle cycles and less dryer time are logical, though nobody has tested them yet.

Does fabric softener prevent pilling?

Unproven. We found no extension or lab source either way.

How do labs test for pilling?

With ASTM D3512 (random tumble) or D4970 (Martindale), rating fabric from 1 to 5, where 5 means no pilling.

Who invented the Martindale tester?

Dr. James Graham Martindale devised it at the Wool Industries Research Association in WWII, and Stanley Dilworth built the first machine in 1942, per trade articles.