What it is: A synthetic-bristle eye definer brush with soft, sturdy bristles. Why it's different: Ideal for use with pressed powder formulas, it delivers just the right amount of shadow onto your lashlines or brows. How to use: If using with an eyeliner, apply as close to the lashline as possible. To fill in your brows, start at the inside corner of the brow and brush upward and outward in quick, short strokes following the natural arch of your brow. Synthetic hair