Manual polishing is a common method to accomplish a mirror-like mould surface, although it is a cumbersome and time-consuming process. It is, thus, of great interest within the industry to find faster and better polishing techniques to decrease the costs and lead times. A key factor towards improved polishing techniques is to find ways to characterize polished surfaces; which parameters and instruments can be used and what is the definition of polishability? This paper summarises a study where three steel grades were analysed with five different measuring devices. The results showed that mechanical stylus instrumentations are not enough to describe very smooth surfaces, but measurement devices with better resolution are needed, such as interferometers