Abstract: A machine makes tapered and also uniformly waved bristles for brushes, especially useful for paint brushes, by a method of applying uniform crimping pressure to crimp straight tapered bristles between two crimping gears (20, 30) having mating indentations. The spacing between the crimping gears is freely variable but the force is generally constant. This results in a wave amplitude that is constant over the length of each bristle regardless of the taper. The "floating" constant-force crimping pressure may be provided by weight biasing or electronic control. Tapered wavy filaments brushes employing such filaments and methods of forming such filaments also constitute a part of this disclosure.