Care & Repair
A wet jumper must be dried flat because water makes it a heavy fabric
Knitted cloth has no internal structure holding it in shape, so a garment full of water hung from a hook will stretch itself out of existence in an afternoon.
Water is heavier than the garment it is in
A dry jumper weighs a few hundred grams. Saturated, it can hold a great deal more than its own weight in water, particularly if it’s made of a fibre that absorbs readily, and all of that weight has to be carried by the fabric itself.
In a woven garment that is survivable, because the interlacing of warp and weft resists extension in both directions and the cloth simply gets heavy. A knit has no such resistance. It is made of loops, and a loop responds to tension by changing shape: pulling longer and narrower, taking yarn from the loops beside it.
Hang a saturated knit and every loop in it is carrying the weight of everything below. The garment lengthens, the shoulders narrow, the body distorts, and by the time it is dry the new shape has been set by the fibres drying in their extended position. It isn’t a stretch that relaxes; it is a new garment.
Getting the water out without abrasion
Wringing is the other common error. Twisting wet knitted fabric applies exactly the combination that damages fibres — moisture, pressure and mechanical rubbing — and in wool it also encourages the scales on adjacent fibres to lock together, which is felting and is irreversible.
The reliable method is unglamorous. Lift the garment supported from underneath rather than by one edge, press the water out gently against the side of the basin, then lay it flat on a clean towel, roll the towel up with the garment inside, and press along the roll. A second dry towel removes more.
A washing machine spin cycle, oddly, is often gentler than hand wringing, because it removes water by centrifugal force without twisting the fabric against itself. On a low spin, in a mesh bag, it is a reasonable option for many knits, though it is the spin rather than the wash that is being borrowed.
Blocking is reshaping while the fibre is still movable
Wet fibres are pliable and they set as they dry, which is a problem when the garment is hanging and an opportunity when it is lying flat. Blocking means laying the damp garment out and easing it into its correct dimensions before it dries, so that the shape it sets into is the one you want.
The method: lay it on a towel on a flat surface where air can reach it, square the body so the side seams are straight and the front and back are aligned, pat the ribbing back to its intended width, and lay the sleeves out straight rather than folded across the body. Measure against a jumper that fits if you are unsure.
This is also how a knit that has already stretched gets rescued. Wash it, then block it smaller and let it dry in that position. It works better on wool and other animal fibres, which have genuine memory, than on cotton, which has very little and will happily stay whatever shape it was last dried in.
Drying flat has requirements of its own
Air needs to reach both faces, so a garment on a solid surface will dry on top and stay damp underneath, which invites mildew and a persistent smell. A mesh drying rack solves this; so does turning the garment over halfway through and replacing the towel beneath it.
Keep it out of direct sunlight and away from radiators. Ultraviolet light fades dye and degrades fibres, and direct heat dries the surface faster than the interior, which can leave a stiff, slightly harsh hand. A cool room with moving air is faster than it sounds and much kinder.
It takes a long time, sometimes more than a day for a heavy garment, and that is the actual reason people hang knitwear despite knowing better. Building it into the routine — washing knits on a day when the space can be spared — is most of the discipline.
Storage follows the same logic
A knit hung on a hanger for months is under continuous tension from its own dry weight, which is far less than the wet weight but applied for far longer. Shoulders develop points where the hanger ends pressed into them, and heavy knits stretch downwards visibly.
So knitwear is folded, not hung, and folded loosely enough that the creases are not being pressed in by the weight of everything above. Heavier garments go at the bottom of the stack for the same reason.
One more habit worth having: make sure it is completely dry before it goes away. Fibre that is even slightly damp when it is folded into a closed space is the beginning of both mildew and a smell that survives the next wash, and by the time either is noticed the season has usually passed.
Common questions
Can knitwear go in a tumble dryer on low?
Some can, and the risk is not only heat. Tumbling combines moisture, warmth and constant agitation, which is the recipe for felting in wool and for accelerated pilling in most fibres. Cotton and synthetic knits tolerate a cool tumble better, and even then the garment usually comes out slightly smaller and slightly less crisp.
Why did my jumper come back bigger after washing?
Because it was dried under its own wet weight, or because the fibre relaxed and nothing put it back. Wool, cashmere and their blends often grow in the wash and can be blocked back to size while damp. Cotton and viscose knits grow more permanently, since neither fibre has much elastic recovery to draw on.
Is a mesh bag worth using?
Yes, for knits and for anything with hardware. It limits how much the garment can stretch and tangle inside the drum, keeps it away from zips and hooks on other items, and reduces the abrasion that produces pilling. It does not reduce the amount of agitation the garment experiences, which is the larger factor.
Tara has written about fit, fabric, care & repair for most of the last decade and prefers a plain explanation to a clever one.