As the name suggests, the Optimized Surface Preparation targets the entire process and this is a decisive factor. As well as maximizing the performance of every individual phase of the process, each step has also been optimized to work perfectly with all the other steps. Mirka’s OSP abrasives are clearly marked with numbers telling which disc or strip should be used for each step. Number 1 is used for paint removal, number 2 for feather edge, number 3 for preparing the repaired area for primer by reducing scratches and expanding the feather edge and number 4 for finalising the sanding.