Final finishing operations of dies and moulds e.g. in the plastic industry, are conventionally performed by manual polishers. With ever increasing demands of shorter lead times and reduced costs, efforts have been made to automate the finishing process. This paper presents the first step towards a built-in surface inspection system for automated polishing processes, designed to indicate when it is time to shift from one preparation step to the next one. It is based on an evaluation procedure for mirror-like steel surfaces, and a characterisation method used to study scratch patterns on cylinder liner surfaces. This method was further developed/adapted to polished steel surfaces. The results showed that scratch width and height were strong indicators for surface quality evaluation.