Warm without the bulk, which is the entire problem with most outer layers.

Why you’ll reach for it every time
You will almost always find me in a knit cardigan with the buttons left open. Big bulky jackets are not for me, and this is the compromise I keep coming back to: properly cosy without the weight or the shape that a heavy coat forces on an outfit.
Worn over a cropped top with jeans, this is close to my perfect outfit. The cropped length is what makes it work, sitting at the waist rather than swamping everything underneath, and the buttons mean you have a closed version for a colder day without buying a second thing. It’s the layer that comes off at lunch and goes back on at six.
WHO WEARS THIS
For the in-between weather that most of the year turns out to be.
The Woman Who Runs Cold in an Air-Conditioned Office: Outside is warm, inside is not. A light cardigan that lives on the back of a chair solves a daily problem.
The Anti-Coat Person: If heavy jackets feel like too much, this is the alternative that still keeps you warm on a cool evening.
The Cropped Top Wearer: A cropped cardigan is the layer that works over a bralet or cropped top and still looks cute.
The Autumn Transitioner: September mornings and September afternoons are two different climates. This handles both without a change of clothes.
