When you first begin to practice your application of acrylic, you will usually make use of a smaller brush which could be a size 6 or 8. These brushes are great to begin with as they effectively lift a smaller beads of acrylic (powder with liquid) allowing you to master your application technique with the 3 zones. They also allow you to learn the ability to get your ratio of liquid to powder correct with more control. However as you begin to advance in your experience and skills, you may find smaller brushes make your application slower and your treatment time longer.