How to distinguish genuine and fake bristle brushes?

Combustion method
Pull off one of the bristles from the brush and burn it with fire. There is a burning smell during the burning process, and it turns into ash after burning. This is the real bristles. The fake bristles are tasteless or have the smell of plastic when they are burned. After being burned, they will not turn into ash, but slag.

Wetting method
Wet the bristles, the real bristles will become soft after wetting, and there is no moisture on the surface of the bristles, and the hair will feel moist to the touch. The fake bristles will not become soft after being wetted, and the surface of the bristles will still be moisture-free, and they will feel dry to the touch without any wet feeling.

Heating
Real boar bristles are heated after being wet, and there will be a peculiar smell when encountering hot water or hot air, but imitation boar bristles do not.

Hand touch method
The boar bristles are soft to the touch and do not have the feeling of sticking hands. They are delicate and elastic to the hand, while the fake boar bristles are harder and lack toughness and elasticity.