A flat foundation brush is a makeup tool designed for applying liquid or cream foundations. Its flat, dense bristles help distribute product evenly across the skin, allowing for a smooth and flawless finish. The shape of the brush makes it easy to reach areas like the corners of the nose and under the eyes. These brushes come in various sizes and materials, including synthetic and natural bristles. Many makeup artists and enthusiasts prefer using a flat foundation brush for its ability to build coverage and create a polished look. Proper cleaning and maintenance are essential to keep the brush in good condition.