The term 'Black Stuff' can refer to two substances: SOOT and TAR. SOOT is a black powdery or flaky substance made of carbon particles that is produced by the incomplete burning of fossil fuels, such as coal or wood. TAR is a black, sticky, viscous liquid composed of hydrocarbons and other organic compounds that is obtained from the destructive distillation of organic materials such as wood, coal, or peat. Both SOOT and TAR are used in various industrial processes, such as road paving and roofing.