The glass inside a cylinder is usually a black glossy substance.

Around the bullet hole in her forehead was a black substance.

The black substance in blackheads, however, has nothing to do with dirt.

Taking a lump of this black substance to product manufacturers wasn't the answer - we needed them to see it in action.

The fingers opened it and a black substance poured upon the paper.

They were walking on a peculiar black substance which seemed to cover most of the area outside the buildings themselves.

Even the black substance beneath her bare feet felt clean and soft.

The can is dry, and thick with a black substance.

The chairs and the couch were covered with a black substance like leather.

Then he noticed a black substance seeping out from under it.