Good knitwear is one of the best investments a wardrobe can hold. A well-made cashmere sweater, properly cared for, outlasts trends, seasons, and most of the fast fashion purchased around it. Yet most knitwear is ruined long before its time through washing too frequently, drying incorrectly, or storing in ways that invite moths. The difference between a sweater that deteriorates after three seasons and one that improves with age is almost entirely care.
Know Your Fibre
Care begins with understanding what you are working with. Different fibres behave differently in water, heat, and storage — treating a cashmere the same as a cotton knit is one of the fastest routes to a shrunken, felted disaster.
- Cashmere is extraordinarily soft but also the most vulnerable knit fibre. It felts irreversibly when agitated in hot water, pills with friction, and is beloved by moths. Handle with maximum gentleness.
- Merino wool is more resilient than standard wool and many merinos are now machine-washable, but always confirm the label. It can handle slightly cooler machine washes in a mesh bag but will still felt in hot or long cycles.
- Lambswool sits between merino and standard wool in terms of softness and requires similar care to merino: cool water, gentle agitation, no wringing.
- Cotton and linen knits are far more forgiving and often machine-washable, but they can stretch when wet and should always be dried flat rather than hung.
- Acrylic blends are typically machine-washable but may bobble more readily than natural fibres and are better served by a delicate cycle and low heat.
How Often to Wash
The single most damaging thing you can do to knitwear is over-wash it. Every wash is a mechanical stress event: fibres rub against each other, stretch slightly, and lose a little of their structure. For natural-fibre knits worn next to a base layer, a wash after five to seven wears is usually sufficient. If you wear knitwear directly against the skin, washing after two to three wears is reasonable.
Between washes, air your knitwear rather than folding it straight back into the drawer. An hour on a flat surface near an open window refreshes the fibre and disperses odour without a single drop of water.
The Right Way to Hand-Wash
Fill a clean basin with cool or lukewarm water — never hot. Add a small amount of specialist wool detergent or a drop of mild shampoo (which is, chemically, very similar to wool wash). Turn the garment inside out, submerge it, and gently squeeze the water through. No rubbing, no wringing, no twisting. Let it soak for three to five minutes, then rinse with cool water of the same temperature — sudden temperature changes shock wool fibres and can cause felting even without agitation.
“Think of wool fibres as hair: the same care that keeps hair shiny and intact keeps knitwear soft and unfelted. Gentle, cool, and not too often.”
Drying Without Distortion
This is where most knitwear is ruined. Never hang a wet knit — the weight of the water will stretch the garment out of shape, creating pulled shoulders, lengthened bodies, and distorted hems that cannot be reversed. Instead, gently press (never wring) excess water out by rolling the garment in a clean towel and squeezing. Then lay the piece flat on a dry towel or a mesh drying rack, reshaping it gently to its original dimensions by hand. Keep it away from direct sunlight and direct heat sources.
Drying time for most knits is 24 hours. Thicker, heavier pieces may need 48 hours. Flip the garment once during drying so both sides air evenly.
Pilling: Prevention and Treatment
Pilling is caused by friction — the short fibres on the surface of the knit tangling together into little balls. It is more common in looser-spun yarns, in areas of repeated movement (under the arms, at the cuffs), and in blended fibres where different fibre lengths sit side by side. Some pilling is inevitable; excessive pilling is usually a sign of lower-quality yarn construction.
To minimise pilling, wash your knitwear inside out, avoid wearing shoulder bags over knitwear, and store pieces folded rather than pressed against rough surfaces. When pills do appear, remove them with a fabric shaver (a small, inexpensive electric device) using a very light touch. Never pull pills off by hand — this yanks attached fibres and accelerates the damage.
Moth Prevention: Non-Negotiable
Moths do not eat knitwear themselves — their larvae do, and they are drawn by any trace of food, skin oil, or perspiration in the fibre. This is why washing knitwear before storage is essential, not optional. Store clean knits in sealed cotton bags or in a drawer with cedar blocks or lavender sachets. Cedar and lavender do not kill moths but they are a deterrent; the only definitive prevention is a sealed environment.
If you find moth damage mid-season, act immediately: wash all affected and nearby knitwear, freeze unaffected pieces (sealed in a bag in the freezer for 72 hours kills eggs), and treat the storage area. A moth infestation contained early loses you one or two pieces; discovered late, it can claim an entire wardrobe.
Storing Between Seasons
Always fold knitwear — hanging compresses and distorts the shoulders over time. Before seasonal storage, wash every piece (even if it has only been worn once), allow it to dry completely, and store in breathable cotton bags or boxes rather than airtight plastic. Include a cedar block or lavender sachet. A drawer that smells of cedar is a drawer where moths do not want to be.
Treated with this level of care, good knitwear is genuinely multi-generational. The cashmere you buy at thirty can be the cashmere your daughter borrows at twenty. That is the real return on investment — measured not in cost-per-wear, but in years of wearing.