The way the brim is shaped ( or flanged) by the maker also makes a difference. Traditional hatters use an iron and a special flanging block. Hat factories often use a machine to press and bake the brim into shape. Many current hat designers, such as Nick Fouquet and his imitators, simply iron the brim flat. Classic brim styles are much more complex.
Bowlers have a tightly curled brim at the sides, whereas Fedoras have sweeping, graceful lines. They and Trilbys often have a so-called "snap", which enables the brim to be flipped up or down at the front. A Porkpie has a fully turned-up brim, while a Homburg is elegantly flanged so that the brim appears to "smile", when viewed from the front. The brims of Cowboy Hats can be totally flat, monstrously curved or anything in between!