(1) Originally, the class of paints consisting essentially of natural bitumens dissolved in organic solvents. They may or may not contain softening agents, pigments, and inorganic fillers. They are usually black or dark in color. Within recent years, the term "bituminous" has, by common usage, come to include bitumen-like products such as petroleum asphalt. (2) A low cost paint containing asphalt or coal tar, a thinner, and drying oils; used to waterproof concrete and to protect piping where bleeding of the asphalt is not a problem.