According to experts, the best acrylic nail brushes are size 8, as they have a precise, pointed tip, and are made from natural kolinsky or sable hair. They are small enough that you can focus the liquid directly where you want, but also large enough to give decent coverage of your nail bed. It’s recommended that you start with a size 6, gradually move to an 8, and then to a size 12, or more, depending on your skill.