pitch.

About pitch

Pitch is a viscoelastic polymer which can be natural or manufactured, derived from petroleum, coal tar, or plants. Pitch produced from petroleum may be called bitumen or asphalt, while plant-derived pitch, a resin, is known as rosin in its solid form. Tar is sometimes used interchangeably with pitch but generally refers to less viscous substances, including some derived from coal production, such as coal tar, and some from plants, such as pine tar.