Tatami mats are the traditional Japanese flooring. Made of woven straw, and traditionally packed with straw (though nowadays sometimes with styrofoam), tatami are made in individual mats of uniform size and shape, bordered by brocade or plain black cloth.
Tatami were originally a luxury item which graced the homes of the well-to-do when most people's floors were made of packed dirt.
There are various rules concerning the number and layout of tatami mats; an inauspicious layout can bring bad fortune. The mats must not be laid in a grid pattern, and in any layout there is never a point where the corners of three or four mats intersect.
In Japan, the size of a room is typically measured by the number of tatami. Shops were traditionally designed to be 5 1/2 mats, and tea rooms and tea houses are frequently 4 1/2 mats.
Tatami mats are associated with Japanese religious rites and the tea ceremony. Most modern Japanese homes still have at least one tatami room.
