Vacuum deposition of a coating consists of a source of the material to be deposited, transport of the material through a low-pressure gaseous (or plasma) environment, and condensation on a substrate. In some cases the depositing material reacts with the gaseous environment, or a co-deposited material, to form a coating of a chemical compound such as a nitride or a carbide (reactive deposition). This category contains manufacturers of materials used in vacuum coating, including sputtering targets and evaporation materials.