Most cardigans are not heavy enough to do anything useful. They sit over a t-shirt, add a vague suggestion of warmth, and then spend the rest of their life at the back of a drawer. A heavyweight cardigan is a different proposition entirely. Worn over a shirt it becomes a proper outer layer for those weeks when a coat feels like too much and a standard knit is nowhere near enough. October is full of those days. So is March.

What we look for is weight without bulk, structure without stiffness, and a button band that stays flat rather than pulling or warping after a few wears. The yarns that hold up best are wool and wool blend, with a tighter gauge than you might expect. These are cardigans that stand on their own rather than propping up another layer. Worn with trousers or good denim they look considered. That is harder to find than it should be.