How to Wash Fleece
Turn inside-out, cold gentle cycle, no fabric softener, low heat or air dry. These four rules cover the most common washing mistakes for fleece.
Fleece sheds microplastics. A Guppyfriend laundry bag captures the fibres before they reach the drain. A single wash can release thousands of microplastic particles.
What Fleece Is Made From
Fleece is a synthetic fabric made almost entirely from polyester — the same polymer as PET plastic bottles. Most fleece is made from recycled polyester (rPET), including many Patagonia and outdoor brand products. The fabric is knitted rather than woven, creating a pile structure where the fibres stand up to trap air and provide insulation. This pile structure is what gives fleece its warmth, softness, and loft. The key vulnerability of fleece is that the individual polyester filaments can break from abrasion and friction — this is what causes pilling (fabric bobbles). When the pile fibres break, they are also released into wash water as microplastic particles (microplastics). A single wash of a fleece jacket can release between 1,000 and 250,000 microplastic fibres, depending on the garment, wash temperature, and spin speed. These fibres are too small to be caught by most wastewater treatment plants and end up in waterways and eventually the ocean. A Guppyfriend laundry bag (or similar microplastic-capturing bag) is the most effective consumer-level tool for reducing this — it captures fibres shed during washing before they reach the drain.
How to Wash Fleece
Turn inside-out before washing
Turning fleece inside-out means the exterior pile surface — which is most visible and most prone to pilling — is protected from abrasion against the drum wall and other garments. The inside surface is also typically where most body contact occurs and where odour concentrates, so turning inside-out also improves cleaning.
Use a Guppyfriend bag or similar microplastic capture bag (recommended)
Place the fleece inside a Guppyfriend laundry bag before putting it in the washing machine. These fine-mesh bags are designed specifically to capture synthetic microfibres shed during washing. The captured fibres can then be disposed of in household waste rather than entering waterways. This is a significant environmental benefit and is strongly recommended for all synthetic fabric washing.
Cold water (30°C maximum), gentle/delicates cycle
Cold water reduces fibre damage and minimises microplastic shedding (heat increases shedding rates). The gentle cycle has lower agitation, which reduces abrasion and pilling. Use a low spin speed if your machine allows — high spin can distort the pile structure of thick fleece.
Use a gentle detergent — no fabric softener
Use a small amount of gentle or sports detergent. Do not use fabric softener. Fabric softener leaves a residue on polyester fibres that clogs the air pockets in the pile structure, reducing the loft and insulating properties of the fleece. It also reduces moisture wicking. This is the same reason fabric softener is avoided for athletic wear and waterproof garments.
Dry on low heat or air dry
Tumble dry on the lowest heat setting, or remove promptly and air dry flat or on a hanger. High heat tumble drying melts polyester fibres — they will not recover. The fleece pile structure can also matt permanently under sustained heat. Air drying is preferable and faster for fleece than it is for cotton because polyester absorbs very little water.
Preventing and Fixing Pilling
Pilling on fleece (fabric bobbles forming on the surface) is caused by abrasion — the polyester filaments break and entangle. The main causes are friction against other garments in the washing machine, high agitation cycles, and physical wear from backpack straps, seatbelts, and bag contact. Prevention: turn inside-out, wash on gentle cycle, low spin, and avoid washing fleece with rough fabrics (denim, Velcro-closure garments). If pilling has already occurred, a fabric shaver (electric lint remover) can remove existing pills and restore appearance — it does not fix the underlying damage but improves the look.
Getting Smell Out of Fleece
Fleece absorbs and retains body odour more than natural fibres. This is because polyester fibres are hydrophobic (water-repelling) but oleophilic (oil-attracting) — they trap the fatty acids and volatile compounds in sweat within the fibre structure. Standard washing removes surface contamination but often cannot reach the compounds locked inside polyester fibres. For persistent odour in fleece: add a tablespoon of white vinegar to the rinse cycle, or pre-soak in cold water with a capful of vinegar for 30 minutes before washing. Sports detergents (Nikwax Basewash, Gear Aid Revivex) are specifically formulated to penetrate polyester and are significantly more effective than standard detergents for odour removal.
How Often to Wash Fleece
Fleece does not need washing after every use unless there is visible dirt or significant sweat. Over-washing increases fibre shedding and pilling. For outdoor/hiking fleece worn over a base layer: wash after 5–8 uses, or when visibly soiled or smelling. For casual wear fleece with direct skin contact: wash after 2–4 wears. Airing fleece thoroughly after each use significantly reduces odour buildup between washes.
By Fleece Type
Microfleece (lightweight, 100–200 g/m²)
Most delicate pile. Cold wash, very low agitation. Air dry. Most prone to pilling from contact wear.
Midlayer fleece (200–300 g/m², Polartec 200, etc.)
Standard care as above. The most common type. Handles gentle machine wash well.
High-pile / sherpa fleece
Very soft, long pile — most likely to matt and lose texture if washed incorrectly. Cold gentle cycle, low-spin, air dry. Do not wring.
Bonded fleece (fleece bonded to woven outer)
The two-layer construction means heat and agitation can delaminate the bond. Cold wash, air dry only — no tumble drying.
Recycled fleece (rPET)
Same care as standard polyester fleece. Recycled content makes no practical difference to washing requirements.
Wool-blend fleece
If it contains any wool content, treat as wool: cold hand wash with enzyme-free wool detergent, lay flat to dry. Wool blend fleece will felt and shrink if machine washed unless explicitly labelled machine-washable.
FAQ
Can you put fleece in the tumble dryer?
Yes, but only on the lowest heat setting. High heat melts polyester fibres and permanently damages the pile structure. Low heat or air fluff (no heat) is safe. Fleece dries quickly because polyester is hydrophobic and absorbs very little water — 30 minutes at low heat is usually sufficient, or 1–2 hours air drying. Never tumble dry bonded fleece (sherpa or fleece with a woven outer layer) as the heat can delaminate the bond.
Why does my fleece smell after washing?
Polyester fibres trap fatty acids and volatile odour compounds from sweat in the fibre structure — they resist release during standard washing. Solutions: use a sports-specific detergent (Nikwax Basewash, Gear Aid Revivex) rather than standard laundry detergent. Add white vinegar (1 tablespoon) to the rinse cycle. Pre-soak in cold water with vinegar for 30 minutes before washing. Avoid fabric softener as it seals the fibres and traps odour compounds further.
How do you stop fleece from pilling?
Pilling is caused by abrasion breaking the polyester filaments. Prevention: always wash inside-out to protect the exterior pile surface, use a gentle/delicates cycle, avoid washing with rough fabrics (denim, zips, Velcro), and use a low spin speed. In use, friction from backpack straps and bag contact is the most common cause of pilling on jacket body panels — a bespoke daypack or pack liner helps. Existing pills can be removed with an electric fabric shaver.
Should you use fabric softener on fleece?
No. Fabric softener leaves a waxy residue on polyester fibres that clogs the air spaces in the pile structure, reducing the insulating loft. It also reduces moisture wicking and breathability, and can trap odour compounds in the fibre. Never use fabric softener on fleece, activewear, waterproof garments, towels, or any performance fabric.
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