Like many school art supplies, paint brushes come in different sizes and shapes, each made for its own purpose. Flat bristle brushes are for more detailed paintings. There are also special preschool brushes that are easier to use, brushes for painting in water colors as well as round bristle brushes. Your child's art teacher should give you a list of necessary brushes or school art supplies for any school art class or school art project. School Art Supplies are available online, and sometimes at a discount. Online purchasing means no running around an expensive art store and trying to find clerks to help you find everything on your art supply list.