The unglazed Catalonian floor tile is red or dark red, which is the typical colour of burnt clay. A small part of the tiles produced are glazed with a red or green transparent vitreous coating (vitrified tiles). The body is made of heterogeneous grain and it is often easy to distinguish the non-homogeneous elements with the naked eye (grains, inclusions, pores). The predominant shapes and sizes are squares and rectangles, but there are many others: hexagons, regular octagons and oblongs and tiles with curvilinear sides. There is a wide range of complementary tiles (mouldings, coves, beads, strips, wads, ...) and especially steps, footrails and drip plates.