Natural rubber vs silicone vs polyurethane mouse pads: Natural rubber wins for flatness if thick enough

Natural rubber stays flatter over time than silicone or polyurethane, but only if the pad is at least 3mm thick and properly cured. Silicone bases are almost immune to curling because they’re molded in one piece, but they feel grippier with less natural glide. Polyurethane foam bases curl most often because the top textile layer and foam expand unevenly.