tatami

Tatami refers specifically to the traditional Japanese flooring system. While often used interchangeably with the word mat, it describes a specific architectural element that defines the size of a room in traditional Japanese housing, where room dimensions are measured by the number of tatami mats they can hold.

Because these mats are made of organic materials like rush grass and straw, they are sensitive to moisture and sunlight. In a modern interior design context, the term is sometimes used to describe any woven grass mat, but in a strict cultural context, it refers only to the authentic Japanese construction.