also known as: Jaw Line Beardsee also: Facial Styles The Chin Strap beard is just a line of facial hair that is essentially an extension of the sideburns that runs all along the jawline. This is a skinnier version of a Chin Curtain, which covers pretty much the whole chin. It can vary in width, but its shape resembles the chin strap on a bicycle helmet. When done right, a Chin Strap shave can draw strength to the jawline.