Brushes play a major role in the final look of a hand-painted oil painting. Natural bristle brushes, such as hog hair, are stiff and good for thick paint and texture. Synthetic brushes are softer and work well for smooth blending and detail. Common shapes include flat, round, filbert, and bright. Artists should choose brushes based on the effect they want. For example, a filbert is excellent for blending edges, while a small round brush is perfect for fine lines. Proper care and cleaning also extend the life of oil painting brushes.