What is it?
All men’s hats are made with some kind of ribbon or band between the crown and the brim. The practical purpose of this is to hide the line of stitches where the sweatband is attached inside the hat.
Since the mid-20th century, Shantung has been used to make more than half of all Cowboy hats in the US plus many stylish Fedoras. The hats are pressed and blocked out of sheets of Shantung.
On vintage Fedoras, the width of the ribbon ranges between 1cm and 5cms, depending on the maker’s taste. The typical ribbon width is 4cms.
Some hats have bands made of felt, leather, horsehair, string or even feathers. They can be quite striking, sometimes with long tails hanging over and down from the brim.
A wide brim Fedora looks outstanding but there's one problem. Sudden gusts of wind can get under the brim and flip it off. In a fraction of a second, your cool image is destroyed and bystanders can enjoy the spectacle of "Man Chasing Hat".
To avoid such embarrassment, some Fedoras are generously provided with a strongly attached cord, which can be unwound and attached to a buttonhole. It looks a bit silly but at least you won't lose your hat.
In parts of Europe there is a tradition of embellishing men's hats with feathers. Following that tradition, many hats are still supplied with feathers tucked behind the ribbon. It's a simple choice to remove it or leave it in place.