Substances applied to other materials to change the surface properties, such as color, wear, and chemical or scratch resistance, without changing the bulk properties. The terms paint and coatings often are used interchangeably. However, it has become a common practice to use coatings as the broader term and to restrict paints to the familiar architectural and household coatings and sometimes to maintenance coatings for doors and windows, bridges, and tanks. Another common term for paint and coatings is finish.