Natural Brushes are used for oil-based paints.
FrogTape® works best with latex or water-based paints which are best applied with synthetic brushes. These brushes keep their shape and maintain stiffness no matter how much water they’re exposed to.
Then, choose a brush size and shape:
Smaller, angled brush is for cutting and trim work.
Flat brush is great for molding.
Larger brushes are used for painting corners or when you’re covering larger surfaces