Cob lighting is a form of indirect lighting built in a ceiling or high on the walls of a room. It directs light up towards the ceiling and down adjacent walls. It is mostly used as primary lighting, especially to highlight decorative ceilings. Cob lighting is valued because it hides the fixtures, and because it provides a very even, warm light.Cob lighting is basically a type of indirect illumination. An indirect lighting system channels indoor light to ceiling level, and then reflects the light back down into the room.