# How to Wash Fleece Without Wrecking the Loft > Polyester fleece hates two things: high heat and fabric softener. Wash it cold with a mild detergent, skip the softener, and dry low or hang. **Published :** 2026-06-08 --- **Summary:** Wash fleece in **cold water with a mild detergent, and skip the fabric softener** — that's the fabric maker Polartec's own method. Polyester fleece is a **thermoplastic** synthetic, so **high heat distorts it**: air-dry, or tumble on low, never high. Check the label before you bleach, and let the **care label** have the final word. This guide is about **synthetic fleece** — the polyester kind in jackets, baby layers and blankets, not a sheep's fleece. The whole method comes down to two habits: keep the heat low and keep the softener away. Fleece is the fabric that makes cheap warmth possible — a soft, lofted synthetic in everything from baby layers to winter mid-layers to the throw on the sofa. It's also easy to dull, and the two usual culprits are a hot dryer and fabric softener. Almost every fleece guide says "wash cold, skip the softener, low heat" — but rarely *why*. The why is what stops you undoing it by accident. One quick clarification, because "fleece" means two things. This guide is about **synthetic fleece** — the brushed polyester knit in jackets, blankets and baby layers — not a sheep's fleece, which is wool and follows the [wool rules](/blog/wash-wool-sweater-without-shrinking/index.md) instead. The good news with the synthetic kind is that it's genuinely machine-washable and quick-drying; the real risks are self-inflicted, from heat and softener — so the routine below is mostly about avoiding those two. > Two reasons sit behind the rules. First, **polyester fleece is a thermoplastic > fibre**, so high heat can distort or damage its surface and finishes > (Britannica) — that's why a hot dryer is fleece's biggest enemy. Second, > **fabric softener and dryer-sheet residue can impair moisture-wicking, > odour-control and performance on technical synthetics**, and fleece is one > (Patagonia) — so the "softness" you add with softener works against the fabric. > Keep the heat low and softener residue off it, and you've sidestepped fleece's > two real risks. Heat is the one that catches people out. Fleece comes out of the wash looking fine, and it's the **hot dryer** that flattens the pile and stiffens the hand — because polyester is thermoplastic, that high-heat distortion is exactly what Britannica describes. So with fleece, the dryer setting matters as much as the wash: a cool, mild wash protects nothing if you finish it on high heat. ## Wash fleece, step by step The method is the fabric maker's own: **Polartec — the original synthetic-fleece maker — says to wash fleece in cold water with a mild detergent and to avoid fabric softeners.** - 🧺 - **A fleece-only load**, turned inside out, zips and Velcro fastened. - ❄️ - **Cold water, mild detergent, no fabric softener** (Polartec). - 🚫 - **Check the bleach symbol**; never mix chlorine bleach with vinegar or ammonia. - 🌬️ - **Air-dry or tumble on low** — never high heat. ### 1. Sort and prep Wash fleece in a **fleece-only load**, turn each piece **inside out**, zip up zips and fasten Velcro, and **lint-roll** off hair and debris first. Fleece is a magnet for lint and pet hair, so a pass with a lint roller before the wash stops it redepositing in the rinse. Keeping fleece away from rougher fabrics and hardware reduces snagging during the wash, and a mesh wash bag is a handy extra for smaller pieces, so they don't catch on zips and hooks. ### 2. Wash cold, mild detergent, no softener Use **cold water and a mild detergent**, and **skip the fabric softener** (Polartec). The softener is the part people get wrong: its residue can impair performance on technical synthetics like fleece (Patagonia), so a plain mild detergent is the better choice — fleece doesn't need softening. ### 3. Mind the bleach For whether fleece can take bleach at all, check the **care-label bleach symbol** and our [bleach-safety guide](/blog/what-fabrics-can-you-bleach/index.md). And whatever you reach for, **never mix chlorine bleach with vinegar or other acids, or with ammonia** — the CDC warns the mixtures can release chlorine or chloramine gases. ### 4. Dry low or hang **Polartec says to tumble dry on low or hang dry**, and to follow the garment's care instructions. The reason to keep the heat down: polyester fleece is thermoplastic, so a **hot dryer can distort or damage it** (Britannica). Air-drying is the safe default; if you use the dryer, keep it on low. And if the care label's tumble-dry symbol gives a specific heat setting, treat that as the ceiling — the label always governs the individual garment (GINETEX). ## What the care label decides The label is the binding instruction, and it sets the limits this guide can't. The **number inside the wash-tub symbol is the maximum washing temperature — a ceiling, not a target** — and a **crossed-out tub means do not wash** (GINETEX). The **tumble-dry symbol caps the dryer** the same way: it tells you whether tumble drying is allowed and at what heat, and a crossed-out tumble circle means do not tumble dry — so when in doubt, air-dry. Fleece rarely needs ironing, but if a label permits it, the **iron dots cap the soleplate** too. When a general tip and the label disagree, the label wins. For the full wash-temperature logic, see our [laundry temperature guide](/blog/laundry-temperature-guide/index.md); for the dryer-heat decision across fabrics, see [what fabrics you can tumble dry](/blog/what-fabrics-can-you-tumble-dry/index.md). ## Fleece blankets and bulky pieces A fleece blanket follows the same rules at a bigger scale. A heavy blanket can overfill a home machine, so give it room to move and rinse; if it can't move freely, use a larger machine. Wash it on its own, cold and gentle, and **dry it flat or over a rail** rather than bunched up in a hot dryer; a very large blanket is often easier in a bigger front-loading machine. A fleece jacket is simpler: do up the zips, turn it inside out, and it washes like any other layer. ## The microfibre question Fleece is synthetic, so there's an environmental footnote worth knowing. **Domestic laundering releases microfibres, and capture devices or lower-friction washing can reduce — but not eliminate — that release** (a peer-reviewed review of marketed capture technologies). The honest framing matters: nothing on the market stops it entirely, so this is about cutting the release, not ending it. The mitigation the research actually supports is two-fold: **lower-friction washing** and a **capture device**. In practice, **wash full loads** rather than one item swimming in a big drum (lower friction between garments), and drop a **fibre filter bag** in the drum to capture part of what does come off. None of it stops the shedding; all of it reduces what leaves your machine. It's the part the cosy-blanket guides skip, and it costs you nothing to do. ## When fleece goes wrong A flat, stiff or pilled fleece is usually a wash problem, not a dead garment — work the cause. - **If it came out stiff after a softener wash, re-wash without it.** Softener and dryer-sheet residue impair performance on technical synthetics like fleece (Patagonia) — use a plain mild detergent and no softener, then air-dry. - **If it flattened or feels scorched, drop the heat.** Polyester fleece is thermoplastic and high heat distorts it (Britannica) — switch to air-drying or a low tumble to avoid any further high-heat distortion. - **If it's pilling, keep the next wash gentler:** cold, inside out, a mesh bag, no softener, air-dry or low heat (the sourced gentle method). A pill-shaver tidies an already-pilled piece. - **Stop if the care label shows a crossed-out tub** — that means do not wash (GINETEX), it's binding, and this guide can't override it. ## Mistakes to avoid > **Warning:** > - **Don't use high dryer heat.** Polyester fleece is thermoplastic, so high heat can distort or damage it (Britannica). Air-dry or tumble on low (Polartec). > - **Don't add fabric softener or dryer sheets.** The residue can impair moisture-wicking, odour-control and performance on technical synthetics like fleece (Patagonia). > - **Check the bleach symbol before bleaching, and never mix bleach.** Never combine chlorine bleach with vinegar or other acids, or with ammonia — the CDC warns the mixtures can release chlorine or chloramine gases. > - **Don't ignore the care label.** The wash-tub number is a maximum, not a target, and a crossed-out tub means do not wash (GINETEX). ## The bottom line Fleece keeps its loft when you respect what it is: a heat-sensitive synthetic that doesn't want softening. **Wash cold with a mild detergent, skip the fabric softener, and dry low or hang** — Polartec's own method — because high heat distorts the polyester (Britannica) and softener residue impairs technical synthetics (Patagonia). Check the label before you bleach, and let it set the ceiling. Two habits carry the whole job: keep the heat low, and keep the softener off. ## Keep reading - [How to wash polyester](/blog/wash-polyester/index.md) — the parent synthetic fibre, and the performance-fabric care behind fleece. - [How to remove pilling from clothes](/blog/remove-pilling-from-clothes/index.md) — how to tidy a fleece that has already pilled. - [What fabrics can you tumble dry?](/blog/what-fabrics-can-you-tumble-dry/index.md) — the dryer-heat decision, fibre by fibre. - [Laundry temperature guide](/blog/laundry-temperature-guide/index.md) — what the wash-tub number means, and why "as hot as it takes" is the wrong instinct.