It is possible to make a boomerang that doesn’t have one edge more rounded; some have a symmetrical, lens-shaped, cross section. The purpose of the airfoil shape is to create lift, so if the boomerang doesn’t have a strong airfoil shape, the tip of the control wing is often twisted, or it has a bevel cut into the tip on the flat side.

Carving the bevel or twisting the wing tip helps the boomerang create more lift. It’s the same effect as when you’re cruising down the freeway, put your arm out the car window and tilt your hand. When you tilt your hand up, your hand flies up. You created lift. Your hand was acting like an airfoil.