How to Store Knitwear
Wash before storing. Fold — never hang. Breathable bags only. For wool and cashmere: cedar protection against moths.
Never hang knitwear. Gravity permanently stretches the knit structure at the shoulders and hem.
Why Hanging Stretches Knitwear Permanently
Knitwear should never be hung on a hanger. The reason is mechanical rather than chemical: knitted fabric is a looped structure — each row of loops interlocks with the next. Unlike woven fabric (where threads run at right angles and create a rigid structure), knit fabric has built-in elasticity and significant give under load. When hung, the weight of the garment acts downward through gravity. The fabric's looped structure allows the loops to elongate under this load over time. The result is gravitational stretch — the shoulders become misshapen (the hanger points pull the shoulder seams down and out), and the body of the garment elongates, particularly at the hem. In natural fibres like wool and cashmere, this elongation can be partially reversed by washing (the fibres shrink back toward their natural length), but the shoulder distortion caused by hanger points is more permanent. In synthetic knitwear, the elongation is often permanent — synthetic fibres do not 'bounce back' through washing in the same way. The correct storage position for all knitwear is folded flat — the fabric weight is evenly distributed and there is no localised tension on any part of the structure.
Moths — Which Fibres Are at Risk
Clothes moths (Tineola bisselliella and Tinea pellionella) are the primary pest threat to knitwear storage, but only for protein-based fibres. The larvae (not the adult moths) eat fabric. They feed specifically on keratin — the structural protein found in wool, cashmere, angora, mohair, alpaca, and silk. They cannot digest cellulose (cotton, linen, bamboo) or synthetic polymers (polyester, nylon, acrylic). This is critical: there is no need for moth protection when storing cotton or synthetic knitwear. Cedar wood contains a natural oil called cedrol, which has a scent that adult moths find repellent and discourages them from laying eggs. Cedar effectively prevents infestations in lightly contaminated environments. However, cedar does NOT kill moth larvae or eggs already in the fabric. If fabric already contains eggs or larvae, cedar will not solve the problem — the infestation will continue regardless. Mothballs (traditionally naphthalene, now more commonly paradichlorobenzene) do kill larvae and eggs through toxic vapour, but both compounds are toxic, carcinogenic in high exposures, and leave a persistent chemical smell in fabric. For most domestic use, cedar repellents combined with clean storage and regular inspection are preferable. If an active infestation is suspected, freeze the affected garments (−18°C for 72 hours) — the cold kills all life stages including eggs.
Storage Steps
Wash all knitwear before long-term storage
Body oils, sweat residues, and skin cells left in fabric will oxidise slowly during storage — particularly in low-oxygen, warm conditions. This oxidation produces yellow-brown compounds that stain the fibre and are very difficult to remove after months of storage. This is the same chemical process that creates yellow armpit stains, but more diffuse. Even items that appear clean should be washed before storage longer than a month. Allow to dry completely before storing.
Inspect for moth damage before storing
Check seams, folds, and collar areas — these areas accumulate skin cells and are the most attractive to moths. Look for small irregular holes (not clean cuts, which indicate damage by something else), tiny white larvae, or small silvery moth cocoons in the fibres. If any of these are found, do not store with other items. Freeze the affected garment (−18°C for 72 hours) to kill the infestation before treating.
Fold — do not hang
Fold each item flat. For sweaters, fold in thirds lengthwise (arms folded across the body), then fold in half from hem to collar. Stack folded knitwear with the heaviest items on the bottom. Avoid more than 4–5 items per stack — the weight of items above compresses those below and can eventually create permanent fold marks in delicate fibres.
Use breathable storage (not plastic bags)
Natural fibres need airflow — storing in sealed plastic bags traps residual moisture and creates conditions for mildew and musty smell. Use cotton fabric storage bags, pillowcases, or purpose-made breathable knitwear storage boxes. The exception: vacuum-sealed bags are appropriate for synthetic knitwear in short-term storage (travel or seasonal) but should not be used for wool, cashmere, or silk long-term as compression can permanently mark delicate fibres.
Add moth repellent for wool, cashmere, silk, and angora only
For protein-fibre knitwear, place cedar blocks, cedar balls, or lavender sachets (lavender oil also has mild moth-repellent properties) in the storage area. Replace or re-sand cedar every 6–12 months as the cedrol oil depletes. For maximum protection, combine cedar repellents with regular inspection — cedar alone is not sufficient defence against a serious infestation.
Store in a cool, dry, and dark location
Heat accelerates fibre degradation. Light (UV radiation) fades colour in natural fibres over months — wool and cashmere are particularly susceptible. Humidity above 65% promotes mildew. A cool bedroom drawer or a dark wardrobe shelf is ideal. Attic storage is poor — temperature swings and humidity spikes accelerate damage. Basement storage is poor — humidity.
By Fibre Type
Wool (all weights)
Wash before storing. Cedar protection essential. Breathable cotton bag. Flat fold.
Cashmere
Wash before storing. Most vulnerable to moths. Cedar + regular inspection. Separate from other fibres.
Merino
Same as wool. Superwash merino is slightly more resistant but still needs moth protection.
Angora and mohair
Very fluffy pile attracts moth eggs. Cedar + airtight breathable bag. Inspect frequently.
Silk knitwear
Moth risk real but lower than wool. Can yellow from oxidation. Wash before storing. Acid-free tissue helps maintain lustre.
Cotton knitwear
No moth risk. Can be hung carefully with padded hangers for shorter storage. Wash before storing to prevent yellowing.
Acrylic knitwear
No moth risk. More resilient to gravitational stretch than natural fibres but can still distort. Fold for long storage.
Wool-synthetic blends
Even small wool content attracts moths. Treat as wool — cedar protection, breathable bag, flat fold.
Common Storage Mistakes
Hanging knitwear long-term
Gravity acts on the knit structure and elongates it permanently — particularly at the shoulders. Hanger points leave visible distortion marks in the shoulder seams.
Storing without washing first
Body oils and sweat oxidise and yellow the fibre during storage. Invisible when stored, they become visible marks after several months.
Using cedar alone as moth protection without inspecting
Cedar repels moths but does not kill larvae already present. An infestation will continue regardless of cedar, just more slowly. Inspection matters.
Storing wool and cashmere in plastic bags
Sealed plastic traps moisture from the air and from residual dampness in the fibre, creating conditions for mildew and musty smell. Use breathable fabric bags.
Stacking too many items
Heavy items on top compress those below, which can create permanent fold marks in delicate fibres like cashmere and angora.
Storing in the attic or basement
Temperature extremes and humidity swings in attic and basement storage damage natural fibres more than any other factor. Use interior room storage.
FAQ
Should you fold or hang knitwear?
Always fold knitwear — never hang it. Knitted fabric is a looped structure with built-in elasticity. When hung, the weight of the garment creates gravitational stretch — the loops elongate under load, permanently distorting the shoulders and lengthening the body of the garment. This is irreversible in synthetic knitwear and often only partially reversible in wool. Fold flat and store in stacks with heavier items on the bottom.
Do moths eat all knitwear?
No — moth larvae only eat protein-based fibres: wool, cashmere, angora, mohair, alpaca, and silk. They cannot digest cellulose (cotton, linen) or synthetic polymers (acrylic, polyester, nylon). Cotton and synthetic knitwear does not need moth protection. Wool-synthetic blends with even a small wool content are at risk. The larvae are attracted to unwashed fabric that contains skin cells and body oils — washing before storage reduces moth risk significantly.
Does cedar kill moths?
Cedar repels moths but does not kill them. Cedar wood contains cedrol — a naturally occurring terpene oil that adult moths find deterrent and that discourages egg-laying. However, cedar does not kill moth larvae or eggs already present in the fabric. If you have an existing infestation, freeze the affected items at −18°C for 72 hours to kill all life stages, then treat the storage area, then use cedar to prevent re-infestation. Replace or re-sand cedar blocks every 6–12 months as the cedrol depletes.
Why do sweaters go yellow in storage?
Yellowing in storage comes from the oxidation of body oils and sweat residues left in the fabric. Even small amounts of skin oil — invisible when you put the garment away — oxidise slowly into yellow-brown compounds when stored in low-oxygen, warm conditions. This process takes months. The solution is to wash all knitwear (including items that appear clean) before storing for more than a month. The oxidation compounds are much harder to remove after they have formed than the original oils are to wash out.
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