 Surface topography plays an important role in the validation of tribological performance of machined parts. The surface topography, particularly the roughness, can provide information about the machining process and can be used as a fingerprint of the manufacturing. However, when using precise measuring equipment such as stylus or optical methods, the definition of the SL surface must be accurate in order to avoid errors in the processing of the data. This paper proposes a method for selecting an appropriate procedure for removing the L and S components from the raw measured data. Different types of surface topographies, including plateau honed, with and without burnished oil pockets, turned, milled, ground, laser textured, ceramic, and composite surfaces, were measured with various stylus and optical methods and parameters from the ISO 25178 standard were also taken into account. It was found that commercially available software methods can be useful and especially helpful in defining the SL surface. This article was authored by Prasemisla Padulka, Wychek Masek, Ricardo Bronco, and others.