This set of Catalyst Polytip brushes by Princeton include four brushes - 10 Flat, 8 Filbert, 6 Angle Bright and 2 Round. Featuring a synthetic bristle hair that is stiff yet still extremely responsive, the Catalyst Polytip has real integrity in water. Each hair tip is split to replicate the finest natural bristle, allowing the Catalyst to hold a higher volume of paint while providing a smoother application. Designed for use with medium to heavy-bodied acrylics and oil paints, Catalyst is able to move heavy gel mediums with confidence.