Pads (polishers) made of a hard-type polyurethane foam sheet are currently employed for glass lens manufacturing because of low wear and simple usage. As innumerable pores of the foam supply and discharge paths of slurry, it is crucial to make the work surface moderately rough in an earlier stage of polishing to enable it to hold abrasives. Figure 6.14 shows SEM photographs of typical polishing pads, such as the polyurethane sheet and artificial leather.