Different types of paint brushes are used for various projects. There are brushes for painting pictures, other brushes for painting walls or trim. And brushes for craft projects are usually very different from the ones used to paint large areas, like walls.
When painting large areas, like a wall, paint rollers and paint sprayers are alternatives to brushes.
- the purpose or type of painting
- type of paint
- repeat use bristles vs disposable sponge (and different materials for the bristles)
Some people have strong preferences for the type of brush they use.
- See the forum discussion on Forum:What do you think the best color is for... ?
- decorating theme
- About.com on Know Your Painting Brushes: Hairs and Bristles: What types of hairs and bristles are used in paint brushes and which are best? By Marion Boddy-Evans
- Wikipedia's article on brush#Paintbrushes