What is Tatami made of?
Tatami are covered with woven soft rush (藺草 igusa) straw. The core is traditionally made from rice straw, but contemporary tatami sometimes have compressed wood chip boards or polystyrene foam cores. The long sides are usually edged (縁 (heri)) with brocade or plain cloth, although some tatami have no edging. The soft covering of the floor mats is woven soft rush straw, or igusa straw, and the very material makes tatami so characteristically comfortable to sit, walk, and sleep on.
As stated above, rush is woven in. Kumamoto, Hiroshima, Okayama, Fukuoka, and Kouchi are famous for growing the ingredient, rush, or Igusa. To make one Tatami mat, 4000 to 7000 rush are used. Today, tatami is made by machines but for the most part of its history, people wove the igusa straw by hand.
The History of Tatami
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, in Muromachi period, when so-called zashiki, entire tatami rooms, came into fashion, and a whole set of layouts and etiquette along with them. Tatami were gradually popularized and reached the homes of commoners toward the end of the 17th century. Modern Japanese homes usually feature only one tatami room, which is called washitsu.
Tatami Sizes and Arrangements
The size of tatami traditionally differs between regions in Japan:
Kyoto: 0.955 m by 1.91 m, called Kyōma (京間) tatami.
Nagoya: 0.91 m by 1.82 m, called Ainoma (合の間, lit. "in-between" size) tatami.
Tokyo: 0.88 m by 1.76 m, called Edoma (江戸間) or Kantōma (関東間) tatami.
There are rules concerning the number of tatami mats and the layout of the tatami mats in a room:
Syugi Jiki (祝儀敷き) is the most popular way done in normal households. The Tatami mats are placed in a way that the 4 corners of the Tatami don't gather in one spot.
Fusyugi Jiki (不祝儀敷き) is used for unlucky events such as funerals. It is a custom in order to avoid the 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!
If the Tatami mat is beyond cleaning and is yellowing, the Tatami mat would be reversed, or changed into a new one. The average Tatami mat life span is around 5 to 6 years.
It is like a fusion of modern and old Japan in one house. Some people prefer sleeping on Tatami mats with Futons, rather than beds on hardwood floors. Some people use the Japanese style rooms for guests.