Although duo-fiber makeup brushes can be used the same way as any makeup brush, Irwin tells us that these brushes have different sized bristles that give your makeup an airbrushed finish. “These brushes are almost always vegan and synthetic-based and work best with liquids and creams,” she says. A large, flat, square-shaped synthetic-fibre brush with a fine firm edge for even distribution and blending of liquid, emulsion or cream products on the face or body. The square shape allows for more control on the level of coverage, which enables the flexibility to work on applying and building ultra-sheer layers. Expensive makeup brushes typically offer enhanced performance with softer bristles for a more even application and tend to be more durable, retaining their shape and structure even after repeated washing and use.