A number of other organic liquids are regularly used in film laboratories for a variety of purposes. Isopropyl alcohol is used to clean joiners and worktops, and some degreasing solvents are used for cleaning metal or painted surfaces of machinery. None of these are satisfactory for film either because they can damage the base or because they produce drying marks. Some solvents are "abrasive" and encourage scratching when wet and in contact with cloth or machinery.