The question that applies to a silk square in June applies again to a scarf in January, with rather more at stake, because in winter a scarf has work to do. The label will say wool, cashmere or acrylic, and those three behave very differently once the temperature drops.
What they actually are
Wool and cashmere are animal fibres: wool from sheep, cashmere from the fine undercoat a goat grows to get through its own winter. Both are protein fibres and both are naturally crimped, which is the whole secret. The crimp holds pockets of still air, and still air is what keeps you warm. Acrylic is a synthetic made from petroleum, spun to resemble wool. It can look convincing in a photograph and feel soft enough in a shop.
Warm, and still warm when damp
The useful difference shows up in bad weather. Wool and cashmere go on insulating when they are damp, which matters more than it sounds, because a scarf meets fog, drizzle, melting snow and the moisture off your own breath. An animal fibre takes a good deal of that water into the fibre itself and keeps holding warm air around you. Acrylic does not insulate the same way once it is wet. It carries the water on the surface, flattens, and begins to feel cold against the skin.
It needs washing less often
Wool resists odour. A wool or cashmere scarf can usually be aired overnight rather than washed, and comes back fresh. Synthetics hold smells, which is why an acrylic scarf tends to need the machine more often, and why it starts to look tired sooner. The fibre that needs less washing generally lasts longer, which is a quiet argument for wool that nobody prints on the label.
Pilling, honestly
Acrylic pills. Those small bobbles that form where a scarf rubs against a collar or a bag strap are the first thing to make a cheap scarf look cheap, and on a synthetic they keep coming back. We should be straight about the other half of this: cashmere pills too, particularly in the first few weeks, while the shortest fibres work their way out. The difference is what happens next. Comb the bobbles off a good cashmere scarf and the surface settles down and stays settled. On acrylic it is the surface itself that is breaking up, and it does not recover.
What acrylic does better
A fair amount, in truth. It costs a fraction of the price. It goes through a washing machine without ceremony, dries quickly and holds a bright colour. Moths take no interest in it, while wool and cashmere want a closed drawer and an eye kept on them over the summer. For a scarf that lives in a coat pocket, gets lost twice a year and is replaced without regret, acrylic makes perfect sense.
The case for the better fibre
What you are really choosing is how long the thing lasts. A good wool or cashmere scarf comes out each November and is still doing its job a decade later, by which time it has outlived several of the cheap ones. It also washes without shedding plastic fibres into the water system, which synthetics are well documented to do. Buy once, keep it somewhere the moths cannot get at it, and the arithmetic settles itself.
Warmth is not something you print on a scarf. It is something the fibre does.
Our winter scarves are wool, made in the same spirit as the silk. See the wool scarves →
