The CFE 6 piece brush set is natural hair brushes.   We recommend that you use natural hair brushes.  Some types of natural hair brushes are sable, squirrel or goat.  This will allow you to achieve the color depth that is shown in our variety of projects.  If using a synthetic or taklon brush you may need to apply more coats because these brushes do not hold as much color as the natural hair.  A natural brush is like your own hair.  It holds moisture when it is wet; therefore, it will hold the water or product you need it to.  A synthetic (man made hair) has a coating on it that is waxy and the product will tend to slide off.  It will not absorb the product.