畳 – tatamu
Tatami is derived from the verb tatamu which means “to fold” or “to pile” which corresponds to the construction of the early tatami mats but also to the fact that they were originally foldable and piled up when not in use.
Firstly, mats were made with a compressed rice straw core (doko) which was wrapped in a braided mat of the same material. Contemporary mats use extruded polystyrene foam or compressed wood chips for the core. The wrapping is a weft-faced weave of soft Igusa grass on a warp of hemp or weaker cotton. The long edges of the mats are finished with a colourful ribbon (heri), with or without a motif.