The thing that catches people out with knitted cardigans is the stretch. Pull one on in the shop over a t-shirt, it looks fitted and neat, then you wear it three times with a jumper underneath and the cuffs have gone baggy and the whole thing hangs an inch longer than it did. It still earns a place in the rotation, because nothing else gives you that same easy layer you can put on without thinking, but go in expecting it to move a bit and you won't be disappointed later.
Mine gets worn over almost everything I own that isn't already bulky. A plain t-shirt and jeans on a cold morning, a shirt underneath with the collar poking out for anything slightly more put together, even over a dress in that awkward bit of the year when the heating's off but it's not quite coat weather. It's the piece that does the job a jacket would do indoors, so I end up reaching for it on days I can't be bothered to think about an outfit at all, which is most days if I'm honest. If you don't own one yet, start with something in a mid weight, not the thin cotton ones that look like cardigans but behave like cotton t-shirts, and not the heavy chunky ones that only work with one pair of trousers in your whole collection. A proper mid weight knit in a colour like oatmeal or navy will go over or under almost anything, and that's the one that gets worn weekly rather than saved for best.
Before you buy, check the buttons are sewn on properly rather than just glued or barely stitched, because that's the first thing to go, usually within a month. Have a look at the ribbing on the cuffs and hem too, give it a stretch with your fingers in the shop, if it springs back it'll hold its shape, if it stays stretched out you've got your answer about how it'll look after a few wears. And check the gauge isn't so loose that your bag strap or a coat zip is going to snag it the first week you own it, fine knits can survive a season of being stuffed into a bag, loose open ones often can't.
After a few washes mine's softened rather than bobbled, which is really the only test that matters, and it still looks like something rather than a sad jumper shape a year in.
Would I still want this after twenty washes and a winter of being shoved in a bag, or does it only look good right now, on the hanger?
Picked by Kirsty Duthie. More in Cardigans.