Tatami mats are woven straw mats closely associated with Japanese culture, where they have been an enduring feature for centuries. The densely woven mats are traditionally used as a floor covering, and a number of traditions surround their use. The classic size of a tatami mat is three by six feet (one by two meters), although a wide assortment of shapes and sizes are available in addition to custom mats. This standard size is often used as a room measurement, much as square footage is used in many parts of the West. Thus, one may hear a room described as “four and a half mats.” Many Japanese import stores stock tatami mats, and they can also be ordered directly.
The early roots of tatami mats were probably simple rushes strewn on the floors of rooms to keep them more dry and clean. Gradually, rushes were replaced with woven mats, which evolved an inner layer of stuffing such as straw or rice bran. Tatami mats are traditionally edged in fabric such as brocade to keep the layers together. Today, the filling for tatami mats is often a synthetic material, designed to resist wear.
Initially, tatami mats were associated with the upper classes in Japan, since only they could afford to commission the large, sturdy wooden mats to cover their floors. A seat on the tatami, rather than the wooden floor, was a sign of social status. Over time, tatami mats became more affordable, until they became a part of the décor of most Japanese homes, along with other features like shoji screens.
Several traditions are associated with the layout of tatami mats in a room. Three or more corners cannot meet, and tatami mats also may not be laid out in a grid pattern. These measures are supposed to promote good health, luck, and fortune, and they are followed in most Japanese homes which still use tatami mats. The straw mats are usually found in traditionally styled rooms, although they may be blended with Western rooms and furniture.
Caring for tatami properly is important. It can mold or become damaged if not handled properly. As a general rule, tatami mats are taken out every three to six months so that they can be beaten, aired, rotated, and replaced if necessary. By tradition, shoes are not worn in Japanese homes, and this cuts down on dirt and potential damage. Tatami mats also cannot get wet, and measures should be taken to dry mats after spills.