A kimono sash is a long flat piece of fabric used to secure a traditional Japanese robe called a kimono by being tied around the garment at the waist while it is being worn. The Japanese term for such a sash is "obi."
Kimono sashes or obi come in a number of different styles. The style, knotting, pattern and material making up the obi all signal social status. Children, adult men and married and unmarried adult women all have different fashions of obi and obi knots. Generally, obi are tied in a flat bow with the ends of the sash placed on the back rather than the front of the wearer. Most kinds are of uniform width, but a very popular style called a Nagoya obi is narrowed along most of its length by being folded over and sewn in half.