Gusset
Gusset is a panel, either triangular or diamond in shape, that is inserted into a garment to help shape and reinforce key points, like the underarms or crotch. You get gussets in modern tights and pantyhose — they add breadth and breathe to the crotch seam. It’s from this panel that that the term ‘don’t bust a gusset’ (don’t rip your pants) originates.
Handkerchief Hems
Handkerchief hems are when the hemline of a dress or a skirt is made up of panels of fabric that fall in points — like the corners of a handkerchief. The technique is particularly suited to bias cutting, drawing the eye away from the hips and thighs and creating the illusion of an elongated lower half of the body.