Paint is any liquid, liquifiable, or mastic composition which after application to a substrate in a thin layer is converted to an opaque solid film.

Paint is used to protect, decorate (such as adding color), or add functionality to an object or surface by covering it with a pigmented coating. Example of protection is to retard corrosion of metal and example of added functionality is to modify light reflection or heat radiation of a surface. Another example of functionality would be the use of color to identify hazards or function of equipment and pipelines.

Paint can be applied to almost any kind of object. It is used, among many other uses, in the production of art, in industrial coating, as a driving aid (road surface marking), or as a barrier to prevent corrosion or water damage. Paint is a semifinished product, or intermediate good as the final product is the painted article itself.

Paint can be mixed with glaze to create various textures and patterns. This process is referred to as faux finish and is quite popular with discerning homeowners, architects and interior designers.