Nylon fibers with birch wood handle.
Westman Atelier Spot Check Brush The tiny pointed brush tip is so precise, which is especially key with concealer: Swirl the brush in concealer (Vital Foundation Stick actually does double duty as concealer), brush the pigment over blemishes, dark circles, or other imperfections, then pat (never rub) with your finger to blend, so the pigment stays where you need it, blending imperceptibly into your skin.