natura - the term refers to the surface of tiles which, after firing, are not subject to additional mechanical treatment; tiles with a natural surface also include textured tiles.
poler - polished surface tiles have undergone complete surface treatment through the grinding of the surface layer, which is made smooth and glossy; unglazed polished gres tiles have their internal pores exposed and require additional impregnation; glazed polished gres tiles do not require additional impregnation because their surface layer is completely vitrified – it does not have internal pores.
lappato - tiles where the surface is partially processed by grinding any protruding elements (usually a glass derivative or structural elements); this gives the tile a partial gloss effect, its surface is made smooth but still has good anti-slip properties; lappato tiles, like all glazed tiles, do not require impregnation.
struktura - this term refers to the surface of tiles which, after the firing process, are not subject to additional mechanical processing, and the uneven face of the tile is formed during the pressing process using a texture press; textured tiles often imitate the texture of the surface of, e.g. natural stone or its symmetrical pattern, which ensures the highest slip resistance class; the use of the texture has a particular effect on increasing the slip resistance properties according to DIN 51097 (the so-called barefoot slip test), in which the test is carried out on a wet surface and the water entering the grooves in the texture does not form an even film on its surface, which significantly improves this parameter and allows the use of these tiles in more demanding places, e.g. wet surfaces next to swimming pools.
