Tatami used to be made of rice straw. Originally, even the core of the mats consisted of this material, while nowadays, usually wood chip boards or polystyrene foam can be found inside the flooring.

The soft covering of the floor mats is woven soft rush straw, or igusa straw, and the very material that makes tatami so characteristically comfortable to sit, walk, and sleep on. Today, tatami is made by machines but for the most part of its history, people wove the igusa straw by hand.

In tatami’s early history, the flooring wasn’t the hard mats that are known today. Instead, they were rather thin and foldable, which is also the origin of the name of the straw mats – tatamu means to fold, or to pile. For a long time, woven mats were exclusive to Japan’s wealthy nobility and even they did not have entire rooms laid out with tatami. It was only around the 15th century when so-called zashiki, entire tatami rooms, came into fashion, and a whole set of layouts and etiquette along with them. The Japanese commoners didn’t get to enjoy proper tatami until the late 17th century. Modern Japanese homes usually feature only one, if any, tatami room which is called washitsu, literally a Japanese-style room.

Interestingly enough, the size of tatami mats vary depending on where you are. In Tokyo, you will find tatami mats that are slightly smaller than those in Kyoto, for example. So a 4 1⁄2 mat room, which is the general size of most tea rooms, might be slightly bigger in the old capital than in the new one.

Besides dictating the size of a room, the arrangement of the individual tatami mats is also important. In the aforementioned tea rooms, this layout changes with the seasons, with the hearth mat being in the middle during winter to keep the room nice and cozy. An “inauspicious” arrangement is said be a bearer of bad luck.

Most people know that it is a common custom to take off your shoes when entering a Japanese home and instead were comfortable slippers when inside. But what about tatami? When it comes to the traditional straw mats, the only proper way to walk over them is barefoot or with socks – not even slippers are allowed. This is done to keep the mats clean as they are easy to vacuum or dust but extremely hard to actually wash.
Whenever you see tatami as a flooring, be prepared to take your shoes off!