Paint brushes are tools used for applying paint, ink, or other substances to a surface. They typically consist of a handle and bristles, which can be made from natural materials like animal hair or synthetic fibers. The shape and size of the brush can vary, affecting the type of strokes and details that can be achieved in a painting. Different types of paint brushes serve various purposes. For example, flat brushes are ideal for broad strokes, while round brushes are better for detailed work. Artists often choose brushes based on the medium they are using, such as acrylic, oil, or watercolor paints.