Between a shirt and a proper coat there is a two month window most wardrobes cover badly. A jacket in wool, twill or denim fills it, provided the cut allows a knit underneath. That fit detail is what separates useful from decorative. The mid-weight layer is the piece most wardrobes are missing, and mild autumns have made that gap wider rather than narrower. A coat is now a six-week garment in most of the country.

A trucker reads casual and layers under a coat later in the year, while a wool jacket can carry a whole outfit on its own. Most people need one of each rather than two of one. Levi's 90s Trucker and Mavi's Rubie are the denim, Rodebjer's Yuna check jacket, Sweaty Betty's cropped wool jacket and the Harris Wharf London pressed wool funnel jackets carry the wool, and AllSaints, Cole Haan and Schott cover the leather bikers. Those are the fall jackets women will find below, in leather, suede, denim and wool, and they are doing genuinely different social jobs despite living in the same slot. One reads off-duty and one reads competent.

The trucker, the field jacket and the blazer between them account for most of what sells in this category, and each came out of a specific working uniform. The trucker is 1960s Levi's, the field jacket is military surplus that reached civilians after Vietnam, and the blazer is nineteenth century rowing kit. Every seasonal variation is one of those three with the proportions moved: Rails' Stafford utility jacket and Free People's Marlo surplus jacket are the field jacket, and Boden's Dartmouth is the blazer. Recognising which archetype a jacket belongs to tells you immediately what it will and will not layer over. It also explains why some of them look wrong with tailoring and others do not.

An unlined jacket is a three-season piece whatever the marketing says, and a quilted or flannel lining moves it into genuine cold. Check the sleeve lining specifically, because a jacket lined only through the body will fight every knit you try to put under it. Satin or cupro sleeve linings let a jacket slide over a sweater instead of dragging it up the arm. Armhole height matters just as much, since a low armhole restricts movement the moment you add a layer. These two details separate a jacket you actually reach for from one that stays on the hook.

Buy the jacket a size up from your usual if you intend to wear knitwear under it, because that is the whole point of this layer. A tight autumn jacket becomes a spring jacket by accident, and a jacket cut with room stays useful for the entire in-between season instead of three good weeks. Sizing up is a simple habit that people consistently refuse to follow, usually because the jacket looks better on the hanger without a sweater underneath it. Check the sleeve lining and the armhole height before the cut, since both decide whether a knit will slide in or fight you every time. Choose room over a perfect fit on the rack, because the fit only matters once the layer is actually on. If you want to keep browsing, I also put together Rain Jackets for Women and Bright Windbreakers and Track Jackets for Fall.