Natural Makeup Brushes
Natural-hair makeup brushes are typically made of different types of animal hair. The most common ones are goat, squirrel, horse, and sable hair, making them more expensive than synthetic brushes. These brushes hold powder products and pigments better than synthetic ones, because the hairs tend to spread out more. So use natural-hair makeup brushes for your eyeshadow, bronzer, and blush. Remember to keep them away from oils and sunlight and let them dry completely after every wash.
Synthetic Makeup Brushes
Synthetic-haired makeup brushes have bristles usually made out of nylon or polyester. The bristles are coated, meaning they can't hold as much product as natural-hair brushes do. Synthetic makeup brushes are perfect for any liquid or cream makeup such as foundation, cream blush, eye liner, lipstick, and concealer.
According to makeup artist Tom Pecheux, "If you use a brush with a cream-based product it must be synthetic, not a natural hair. If it’s a cream blush or cream eyeshadow or lipstick or foundation, you must use all synthetic brushes. First of all, because these products are greasy, so it’s much healthier to use a synthetic, and also because synthetic brushes are flat."