Illustrated Japanese Culture
Tatami: the mat that became a floor
畳（たたみ）
Tatami are fitted mats used for sitting and sleeping in Japanese-style rooms. A mat has a supporting core, a woven surface and usually cloth borders.
01
Inside a mat
Core, surface and border
The core, tatamidoko, supports the mat. It may consist of compressed, sewn rice straw, straw surrounding a foam board, or manufactured boards and foam. The cover, tatamiomote, is attached over it. Cloth borders, tatamiberi, protect the cut edges along the two long sides.
From rush to a woven cover
Traditional covers weave rush across hemp or cotton warp threads. In Kumamoto’s documented process, harvested rush is treated with natural clay, dried, sorted by length and woven. The coating helps even drying and preserves colour. Manufactured covers may instead use paper or polypropylene.
Fitting the room
Makers fit each mat to the room and align patterned borders, including when restoring historic interiors. Border patterns once indicated rank. Ornamental kōraiberi and ungenberi remain part of the specialist work needed in historic buildings.
02
Dimensions and renewal
The size behind the mat count
Examples include kyōma at about 191 × 95.5 cm and Edoma at about 176 × 87.8 cm. These are named sizes, with local variation; the mat count alone does not give an exact area.
Full, half and shortened mats
Full mats are generally twice as long as they are wide. Chūkyōma measures about 182 × 91 cm and danchima about 170 × 85 cm. Half mats are generally square; tea rooms also use the shortened daimedatami, about three-quarters of a full mat’s length. Ordinary mats are commonly 55–60 mm thick, while thin versions may be 15–30 mm.
The area shown in property listings
Under the fair-competition advertising rules, room size expressed in jō must allow at least 1.62 m² per advertised mat, calculated from wall-centre area divided by the mat count. This is an area-description rule; it does not give the dimensions of each fitted mat.
Arranging the joints
The common shūgijiki arrangement staggers rectangular mats so that four corners do not meet. Fushūgijiki places mats in aligned rows with cross-shaped junctions and was associated with occasions such as funerals. Modern borderless half mats can also form a checkerboard by alternating the weave direction. Individually fitted mats normally return to their original positions after recovering.
Replacing a worn surface
Omotegae replaces the cover and borders while retaining a sound core. Uragaeshi removes the existing cover and remounts it with the reverse side exposed: the whole mat is not turned upside down. A new mat replaces all these components.
Cleaning a rush surface
Vacuum gently along the weave. Use a dry or thoroughly wrung-out cloth, avoiding excess moisture. Ventilation and removal of dust and food crumbs reduce conditions that support mould and mites. Covering tatami with a carpet can trap moisture.
04
From individual seats to furnished rooms
A surviving bed-mat fragment
The Shōsōin preserves a fragment of a mat once placed on a bed platform. Imperial Household Agency examination identified a woven rush surface over layers of plaited makomo leaves. This surviving object shows an early combination of cover and core, with materials different from a later rice-straw core.
Left: Front and back of the Shōsōin bed-mat fragments, originally used on a raised bed. Right: Edge detail showing the fine woven rush surface, plaited core and hemp backing.- Movable matsPlaced where needed
- Elite medieval roomsWall-to-wall flooring
- Early modern homesWider, uneven adoption
Ancient and Heian uses
Early uses of the word tatami covered several kinds of layered mat. In Heian elite residences, movable mats provided places to sit or sleep on wooden floors; their dimensions and borders could mark status.
A late-Edo Genji illustration depicts mats in an earlier aristocratic setting.Medieval rooms
Elite Muromachi residences increasingly used wall-to-wall tatami; adoption in ordinary housing continued into the early modern period.
Edo tea rooms and homes
Tatami flooring spread in tea rooms and gradually into townspeople’s homes. Adoption varied between households and places.
Left: A diagram of an Edo townhouse places matted rooms beside an earthen-floor workspace. Right: Mat makers working on tatami, reproduced on the industry association’s history page.05
Modern housing changes the market
- Meiji–TaishōMore urban housing
- Postwar estatesMats fitted to apartments
- 1998 reportFewer washitsu, weaker demand
Meiji and Taishō
Six- and eight-mat rooms were common arrangements in Meiji housing. Growing urban populations and housebuilding in Taishō increased demand for mats.
Postwar apartments
Large-scale apartment construction brought smaller danchi-size mats into use. Housebuilding during rapid economic growth supported the industry.
A downturn recorded in 1998
A government response in 1998 linked falling demand for tatami covers to fewer Japanese-style rooms and a sharper decline in new housing after June 1997.
- Colonial periodIntroduced with Japanese-style buildings
- 1947Quansing opens
- Later generationsCustom work and new materials
Transmission to Taiwan
Tatami entered Taiwan with Japanese-style buildings and living practices during Japanese colonial rule. Tainan’s Quansing shop opened in 1947. Later generations continued the craft while adding materials and custom designs for homes, hotels and dining spaces.
06
Preservation and new forms
Keeping specialist skills
Traditional tatami-making was selected as a cultural-property conservation technique in 2004. Kyoto makers also produce mats for shrine and temple ceremonies as well as homes and tea rooms. In 2020 it became part of UNESCO’s inscription of seventeen traditional architectural craftsmanship techniques.
Thin mats and new settings
Thin, borderless and modular mats allow partial coverage. In 2023, Kuboki opened Tatami Village, combining manufacturing, a showroom and a café.
What can you now explain?
What are the three main parts of a traditional tatami mat?
The supporting core is tatamidoko, the woven cover is tatamiomote, and the cloth borders along the long sides are tatamiberi.
Why can two six-mat rooms have different floor areas?
Named mat sizes differ: for example, kyōma is larger than Edoma. Six mats therefore do not always cover the same area.
What changed when movable mats became wall-to-wall flooring?
Tatami changed from a movable place to sit or sleep into a room’s continuous floor surface, spreading beyond elite interiors over time.
How have housing and newer materials affected tatami?
Modern housebuilding supported demand, while fewer Japanese-style rooms later reduced it. Manufactured cores and paper or resin covers also expanded the available forms.
What does each layer and border do?
The core supplies support and thickness, the cover provides the exposed surface, and the borders protect the cut long edges.
How does a listing’s jō measure differ from a physical mat?
An advertised jō is an area measure requiring at least 1.62 square metres per unit under the rule; it is not a measurement of each installed mat.
How do staggered rectangular mats and a half-mat checkerboard differ?
Staggered rectangular mats avoid four-corner junctions. A modern half-mat checkerboard uses square mats with alternating weave directions.
Which part is reversed in uragaeshi?
The woven cover is removed and reattached with its reverse showing. The entire mat is not flipped over.
How are Ryūkyū and judo tatami different types?
Traditional Ryūkyū tatami uses shichitōi, though the commercial name now covers other borderless materials. Judo tatami is specialized sports equipment with its own cushioning and standards.
Sources and images
Object photographs, historical images and reading sources are listed below.
- 畳製作
- 畳の歴史
- 畳の種類
- 京たたみ
- 畳屋の事業転換と両利きの経営者
- い草産地救済に関する質問に対する答弁書
- 畳の構造
- 畳表ができるまで
- い業ガイド
- 畳を知る
- 畳の購入に関するFAQ
- 不動産の公正競争規約・施行規則
- 畳のお手入れ
- いぐさ畳のお手入れ
- 国東だけで育つ七島藺
- 公認柔道畳
- 柔道畳の部材について
- 泉興榻榻米
- 臺南奇人帶路：榻榻米
- 伝統建築工匠の技
- 畳の敷き方
- 正倉院宝物特別調査 筵調査報告