In the recently completed EU project TracOptic, a Good Practice Guide (GPG) has been developed to aid in the selection of instrumentation for optical surface texture measurements using confocal microscopy, coherence scanning interferometry, and focus variation instruments. This guide outlines several criteria and steps for selecting the appropriate instrument and objective, where validation of optical surface texture measurements by comparison with reference measurements using AFM or a stylus profilometer remains crucial. AFM reference measurements are needed for surfaces with high-frequency structures, whereas stylus reference measurements are sufficient for classical technical surfaces with relatively low-frequency structures and limited surface slopes. In this paper, we focus on the validation of optical measurements with stylus profilometers on technical surfaces with moderate local slopes. Marks have been applied to the test surface to ensure that both optical and stylus-based methods measure at exactly the same surface location. Two comparison methods were developed: 1) Profile Matching: Aligning and matching the measured stylus profiles with the corresponding optical measurements; 2) Statistical Comparison: Evaluating the statistical consistency between results from stylus profilometry and optical measurement. For the second method, simulations were carried out to determine the minimum number of evenly distributed profiles required to obtain optical surface texture height parameters (e.g. Sa and Sq) within a ±2.5% tolerance. Experimental investigations were then carried out based on these simulation results. A milled technical surface with marked areas corresponding to the field of view (FOV) of different microscope objectives (i.e., 20x, 50x, and 100x) has been measured using a confocal laser scanning microscope and a stylus instrument. The comparison results for both methods are presented in this paper. The methodology developed for stylus instruments can also be applied to AFM as a reference instrument for validating optical surface texture measurements.