Nylon bristles are often stiffer than boar bristles. Use a nylon bristle brush to penetrate thick hair and for detangling hair. Boar bristles are usually softer than nylon. Use a boar bristle brush on fine, thin or damaged hair and for brushing out a style to create a fuller look. Boar bristle brushes are gentler the scalp and help distribute natural oils to give hair a healthy-looking shine.