How to Fix a Sweater That Pilled After Washing

You knitted a sweater. You washed it. You pulled it out of the laundry and it's covered in small, fuzzy balls of yarn that have tangled themselves to the surface of the fabric. This is pilling, and it's fixable. It is also, in many cases, preventable — but if you're already here with a pilled sweater, let's start with the fix.

What Pilling Actually Is

Pilling happens when short fibres in the yarn work their way out of the twist and tangle together on the surface of the fabric. Every time the sweater is worn or washed, friction pulls more fibres loose. Those loose fibres catch on each other and form the small balls (pills) you're looking at now.

Pills don't mean the sweater is ruined. They mean the shorter fibres have already migrated to the surface — once you remove them, the remaining longer fibres that make up the body of the yarn are more stable, and the sweater will pill less going forward.

Which Yarns Pill Most

Understanding why your yarn pilled helps you prevent it in future projects:

Low-twist singles: Yarn spun as a single strand with minimal twist has fibres that escape easily. Beautiful to knit with, lovely drape, pills readily.

Short-staple fibres: Some merino wool (especially fine micron grades), angora, and some acrylic blends have short individual fibres that pull out easily. High-quality merino with a long staple pills significantly less than budget merino.

Acrylic: Acrylic pills vigorously because the fibres are thermally fused at the ends rather than naturally locked by wool's microscopic scales. Acrylic pills are also harder to remove cleanly because the fibres are very strong — they don't break off easily.

Blends with both wool and synthetic: The wool fibres break off cleanly; the synthetic fibres hold them on the surface. Blends often pill more than either component would alone.

How to Remove Pills

Option 1 — Electric fabric shaver (best method): A fabric shaver has a small spinning blade behind a perforated guard that cuts the pill stalks cleanly. Lay the sweater flat on a hard surface. Work the shaver in small, gentle circles, letting the blade do the work without pressing hard. Empty the lint compartment frequently. Result: a surface that looks nearly new.

Cost: £10-25 for a good one. Worth it if you own natural fibre knitwear. Do not use the cheapest shaver you can find — cheap blades snag rather than cut and can damage the fabric.

Option 2 — Disposable razor: A standard single-blade disposable razor, used very gently with short upward strokes on a flat, taut surface. The razor cuts the pill stalks. Requires care — too much pressure will snag or cut the yarn beneath the pill. Good for small areas. Not recommended for anything other than flat fabric in good condition.

Option 3 — Sweater stone: A pumice-like block that you drag across the surface to catch and break pills. Slower than an electric shaver but gentler and precise. Good for delicate fabrics or areas where you want control. Available from most yarn shops.

Option 4 — Velcro strip: A small strip of hook Velcro (the rough side), dabbed gently on the surface. Catches pills without cutting. Very gentle, very slow, good for extremely delicate fabrics or small isolated patches.

After Removing Pills: Preventing the Next Round

Once the pills are gone, the sweater's condition has actually improved. Here's how to keep it that way:

Hand wash in cool water. Machine washing — even on delicate cycles — creates friction. Hand washing in a bowl of cool water with a small amount of wool wash is gentler.

Use a mesh laundry bag. If you must machine wash, put the sweater in a mesh bag on the delicates cycle. The bag reduces friction significantly.

Turn the sweater inside out. Most pilling happens on the outside surfaces that contact other clothing. Wearing it inside out isn't practical, but washing it inside out reduces friction during the wash cycle.

Skip the dryer entirely. Heat and tumbling are the most aggressive combination of friction and stress you can apply to knitted fabric. Always dry flat.

Wash less frequently. Every wash cycle removes some fibre from the surface. Air the sweater between wears — most knitwear only needs washing every 3-5 wears.

Which Yarns Pill Least

If you want to avoid pilling in future projects, choose yarns from these categories:

Long-staple wool: Shetland, Swaledale, and Bluefaced Leicester wools have long fibres that interlock well and resist pilling. They feel scratchier than merino but wear beautifully and improve with age.

Tightly spun yarn: The tighter the twist in the plying, the harder it is for fibres to escape. Hold two yarns at the same weight and compare twist — choose the one with more twist if pilling is a concern.

Superwash wool: The superwash treatment removes the fibre scales that normally cause felting, and also tends to reduce pilling because the treatment partially fuses the fibre surface. Not always pill-free, but typically better than untreated equivalents.

Linen and cotton: Plant fibres don't felt and pill differently to wool — cotton can pill, but plant fibre pills break off cleanly and the fabric remains usable.

The most pill-resistant knitted fabric is a tightly spun, long-staple wool yarn knitted at a firm gauge on slightly smaller needles than the ball band suggests. This isn't always what you want aesthetically — but for outerwear that needs to last years, it's worth considering.

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