As a rule, buy the best brushes you can afford. They will do a better job and, with care, can be reused many times. Quality paintbrushes have hardwood handles and flagged or split-bristle tips that hold more paint. Their bristles
are anchored at the top with metal or plastic spacers inside a metal ferule. They are tapered at the bottom to deliver a sharp paint edge.
Less-expensive brushes may have plastic handles, unflagged bristles, and blunt ends. Their bristles may be anchored or spaced less securely and be coarser and stiffer-textured, producing more-noticeable brush-stroke marks.
The choice between synthetic and natural bristles should depend on the type of paint you are using. Synthetic or nylon brushes are best suited to water-based paints because they do not absorb water and they maintain consistent stiffness throughout.
Natural-bristle brushes are recommended only for oil-based paints — they absorb the water from latex paints and turn limp, making it difficult to load a brush with paint or keep an edge. For general home painting or decorating, you will need at minimum a sash brush, a trim brush, and a broader wall brush.