Basically, there are two kinds of mechanical procedures which depend on the movement of the polisher. 1. In the rotary method, the polishing pad is rotated at high speed on a backing disc over the paint surface. This procedure is extremely abrasive and should therefore be used on heavily weathered paints. Due to the different force in the interior of the rotation axis and the outside area, frequent hologram formation is to be expected. 2. The eccentric method is tuned so that the rotary motion is interrupted through an orbital transfer. This therefore prevents the formation of holograms. The full power of the rotational speed, however, cannot be transferred onto the pad. This consequently results in lower abrasiveness. The stroke of each machine is particularly important in this context for the efficiency of the procedure. Orbital machines with a low stroke generally used for sanding purposes are, therefore, unsuitable for polishing. Only machines specifically designed for polishing applications, i.e. dual-action polishers with an orbital stroke of minimum 10 mm, should be used.