Tatami

The term tatami is derived from the verb , meaning 'to fold' or 'to pile'. This indicates that the early tatami were thin and could be folded up when not used or piled in layers. Tatami were originally a luxury item for the nobility. The lower classes had mat-covered earthen floors. During the Heian period, when the shinden-zukuri architectural style of aristocratic residences was consummated, the flooring of shinden-zukuri palatial rooms was mainly wooden, and tatami were used as seating only for the highest aristocrats. Tatami were gradually popularized and reached the homes of commoners toward the end of the 17th century. Houses built in Japan today often have few or no tatami-floored rooms. Having just one such room is common. Rooms having tatami flooring and other such traditional architectural features are referred to as nihonma or washitsu, "Japanese-style rooms". File:Saikū Historical Museum - Display item04 - The palace of Saiô - Miniature model.jpg|Green tatami in a museum model of the Saikū palace in ~the 9th century File:Gaki zoshi - Tokyo - part 1.jpeg|Courtiers making music, circa 1150-1200 File:Otomo no Yakamochi Agedatamibon.gif|As a dais, ~13th century File:Tengu zoshi, Nezu Museum scroll, detail 2.jpg|An almost-completely-covered floor in an illustration drawn in 1296 File:Sleeping two, Kasuga Gongen Genki (1309).jpg|Tatami being used as sleeping mats, 1309 (see futon) ==Size==

Tatami can be categorized by their size, correlated to their place of origin: • tatami: , originated from Kyoto • tatami: , also called tatami, originated from Nagoya • tatami: , also called tatami, originated from Tokyo In terms of traditional Japanese length units, a tatami is 1 by 0.5ken, or equivalently 6 by 3shaku. The length of these units varies regionally, which led different regions to develop separate tatami size conventions. One shaku is approximately the same length as one foot in the British-American measurement system. As for thickness, is average for tatami, while is the norm for tatami. A half mat is called a , and a mat of three-quarter length is called a ( or ), which is used in . tatami do not have borders, and have become popular in modern times for their simplicity. ==Layout==

There are rules concerning the number of tatami mats and their layout in a room. In the Edo period, and tatami arrangements were distinctly differentiated, with tatami rearranged depending on the occasion. In modern practice, the "auspicious" layout is normally used. In this arrangement, the junctions of the tatami form a "T" shape; in the "inauspicious" arrangement, the tatami are in a grid pattern wherein the junctions form a "+" shape. It is NP-complete to determine whether a large room has an auspicious arrangement using only full mats. An inauspicious layout was used to avoid bad fortune at inauspicious events such as funerals. Now it is widely associated with bad luck and itself avoided. File:JapanHomes101 ARRANGEMENT OF MATS IN DIFFERENT-SIZED ROOMS.jpg|Some auspicious layouts from the early 1800s (Edo Period) Image:Tatami layout 1.svg|One possible auspicious layout of a  mat room Image:Tearoom layout.svg|Typical layout of a  mat tea room in the cold season, when the hearth built into the floor is in use. The room has a tokonoma and mizuya dōko Image:Youkoukan06n4592.jpg|Room with tatami flooring in an inauspicious layout and paper doors (shōji) File:Anforet 3F 2017-06-02 ac (2).jpg|An auspicious layout File:ITatami (8465411258).jpg|"T" shape File:Tatami (51687126569).jpg|Ryūkyū tatami are square shaped without borders ==See also==