Light that enters a material and is trapped (neither reflected nor transmitted).

Light which is not reflected or scattered by a light-opaque substance is absorbed by the material and mostly turns into heat. Matt black material, such as the flocked black lining commonly applied to the interior of lens hoods, absorbs a great deal of light, thereby reducing the risk of flare. And what light is not absorbed by the material is mostly scattered within the flocking. Similarly, dark fabric panels can be used to prevent light reflections onto a subject.