Good wool socks are chosen by three things: the fibre (alpaca, merino or sheep's wool), the thickness (for a shoe, a boot or the sofa) and the size (a wool sock must not be big, it stretches on its own). The fibre decides whether the sock itches and whether it smells after a long day; the thickness decides where it fits. All three choices in numbers below.

Material: alpaca, merino or sheep’s wool

AlpacaMerinoSheep’s wool
Warmth per weighthighest (hollow fibre)mediummedium
Moisturerepels, dries fastabsorbs up to 30 %absorbs
Smell after a long dayminimalslightnoticeable
Itchno itch (under 26 µm)no itchitches for some
Durabilityhighmedium, needs syntheticshigh
Lanolinnoyesyes

Alpaca fibre is partly hollow like reindeer hair, so it holds more warmth per gram than merino, and since the fibre carries no lanolin it also suits wool-sensitive skin. We explained why in the fibre guide. Against cold toes, alpaca is, as far as we know, the best natural answer.

Thickness: which sock goes where

Our socks are knitted from alpaca yarn in three thicknesses, and the right choice depends on the footwear going over them:

SockPriceFits
Thin alpaca socks22 €regular shoes, the office, daily wear
Medium alpaca socks27 €winter boots, hiking boots, cool evenings at home
Extra-thick alpaca socks32 €wellies, hunting and fishing, instead of slippers at home

Rule of thumb: if the sock goes into a closed shoe, pick the thinner one; otherwise the shoe gets tight and the foot freezes anyway, because compressed wool no longer holds the air that keeps the warmth in. For truly cold floors there are also baby alpaca fur slippers.

Alpaca wool socks in three thicknesses on a wooden table

Size: pick a wool sock exactly

A knitted wool sock stretches about half a size with wear and moulds to the foot. So choose your normal size, or the smaller one if you sit between sizes, never the larger: an oversized sock creases inside a boot and rubs. There is no breaking-in period; a wool sock is soft from day one.

Buying as a gift? Of the three thicknesses the middle one is safest: it works in a boot and at home alike. The rest of the gift question we thought through in the gift ideas article.

So the socks last for years

Wool socks do not need washing after every wear: alpaca fibre does not hold smell, airing is usually enough. When you do wash, do it by hand or on a wool cycle at up to 30 °C, with wool detergent, no spin, and dry flat. Radiators and tumble dryers felt wool permanently. The full guide is in the care article.