Disc brushes are used for deburring, finishing and polishing. Twisted-in-wire brushes are commonly used for internal deburring and cleaning. Metal back strip brushes are manufactured for internal and external surface finishing. Ferrule end brushes are used for deburring and finishing.Roller marks are exactly what they sound like — evidence of where the painter used the roller brush. They are often caused by a painter putting a second coat of paint on the wall before the first coat has completely dried.