The Mason Pearson Hairbrush cleans the hair and stimulates the scalp, increasing blood flow to the roots. Pure Bristle brushes: For fine to normal hair, fine long hair. The Child's model for children aged between 3 and 6 years. Boar bristle is used because it has a natural affinity to human hair. That is to say, the structure of Boar bristle is similar to human hair. The affinity makes the boar bristle cling to the hair shaft, to accomplish the purposes of hair brushing.