IPSA Brush for Pressed Powder Control powder brush for a soft, matte finish. A flat brush made of horsehair, designed for gentle application and easy blending, to give pressed powder a light, matte finish. How to Use: Keep the brush clean, as powder will not adhere well if it becomes dirty. If the brush gets dirty, lightly wash it in lukewarm water with a small amount of neutral detergent. Rinse thoroughly to remove any detergent, blot excess water with a dry towel, and let it dry completely in the shade before using.