Brushes are the oldest and most versatile applicator. It's almost impossible to complete a paint project without one. There are basically two types of bristles... natural and synthetic.
How to Select the Right Paint Brush
Natural bristle brushes can be used with oil based paints and varnishes. But, since natural bristles absorb water, they're not a good choice for use with latex paints. Natural bristles absorb water in latex paint, eventually making the brush soft, floppy and unmanageable.
Synthetic bristle brushes, on the other hand, can be used with any type of paint. However, you should be aware that some synthetic brushes have smooth, glass-like bristles that don't hold or spread paint very well. But not Do it Best synthetic bristle brushes. They use patented bristles called BRISTLEON, which are not affected by moisture and have a rough surface that holds and spreads any paint effectively.