Many Japanese martial arts feature an as part of their exercise outfit. Such an obi is often made of thick cotton and is about 5 cm (2 in) wide. The martial arts obi are most often worn in the koma-musubi knot (square knot); in practice where a hakama is worn, the obi is tied in other ways.
In many martial arts, the colour of the obi signifies the wearer's skill level. Such colours usually start from white for beginners and end in black or red-and-white for masters.
The colour of the obi signifies the wearer's skill level in certain martial arts. Such colours typically start from white for beginners and progress through yellow, orange and red (in varying order), green, blue, brown, and culminating in black for masters. In some cases stripes are added to distinguish additional levels, or the rank of a master beyond the 1st dan.
The red obi has the greatest variation among martial arts rankings. In some martial arts it is used for the highest dan ranks, the founder of a style or a grandmaster, while in others it designates a low or unranked beginner.
The obi is most often tied with the koma-musubi knot, which resembles the reef knot (see diagrams).
In several martial arts, an obi is worn but with a single colour across all competition classes or with a colour which carries no significance. In some of these cases, a hakama is worn which covers the obi.
Unlike in many other martial arts, an adult practitioner of aikido does not traditionally wear a coloured obi,[3] though in some schools different colour codes have been formed, especially for children. A child's obi ranges from white for beginner level to 7th kyū, other colours for the rest of the kyū levels, and black for levels 1st dan and up.[4]
In some aikido schools, wearing a hakama is a privilege earned by reaching the first dan level. In other schools, all practitioners may wear a hakama. Once using a hakama, the colour of obi does not matter since it will be covered by the hakama.
Below is a typical example of obi colours by level in aikido:
| Level | Obi colour | |
|---|---|---|
| 6th kyū | yellow | |
| 5th kyū | orange | |
| 4th kyū | green | |
| 3rd kyū | blue | |
| 2nd and 1st kyū | brown | |
| 1st–3rd dan | black | |
| 4th–9th dan | black and red, or white and red | |
| 10th dan | dark blue |
However, aikido schools worldwide may use their own systems with little reference to other schools save the use of a black belt for at least some dan grades.
The makes use of only a limited set of belt colours, however there are also different associated uniform emblems or, the style of which varies dependent on the grade of the Budoka. Unlike many other martial arts, the number of Dan grades extends to Jūgodan (15th Dan), and practitioners at this grade of may also be gifted the status of by the Sōke.[5] This title also comes with its own wappen style featuring a purple background.
| Level | Obi colour | |
|---|---|---|
| without grade (Mukyū) | white | |
| Kyū grades | green | |
| Dan grades | black |
Below are the colours of obi worn for judo practise. Junior practitioners have a different colour range.[6] There are also other colour ranges used worldwide.
| Level | Obi colour |
|---|---|
| Beginners | white |
| 5th kyū | yellow |
| 4th kyū | orange |
| 3rd kyū | green |
| 2nd kyū | blue |
| 1st kyū | brown |
| 1st–5th dan | black |
| 6th–8th dan | red and white |
| 9th and 10th dan | red |
The following table lists standard colours for obi used for ju-jitsu practise,[7] and alternative colours that may be used by different ju-jitsu federations.
| Level | Obi colour[8] | Alternative | |
|---|---|---|---|
| beginners | white | red | |
| 10th–8th kyū | red | white | |
| 7th kyū | white with a red stripe | yellow | |
| 6th kyū | yellow | orange | |
| 5th kyū | orange | green | |
| 4th kyū | green | blue | |
| 3rd kyū | blue | purple | |
| 2nd kyū | violet | brown and white | |
| 1st kyū | brown | brown | |
| Shōdan-ho | brown and black ("temporary black") | n/a | |
| 1st–5th dan | black | black | |
| 6th dan and higher | red and white | n/a |
The following table shows karate ranks and the respective obi colours worn by adults in the major styles: Kyokushin, wadō-ryū, Shotokan KUGB, and Shitō-ryū.
| Level | Obi colour | ||||
|---|---|---|---|---|---|
| Kyokushin[9] | Wadō-ryū[10] | Shotokan[11] | Shitō-ryū[12] | ||
| mukyū (beginner) | white | white | n/a | ||
| 10th kyū | orange | turquoise | white | ||
| 9th kyū | orange + stripe | red | orange | yellow/white | |
| 8th kyū | blue | yellow | red | yellow | |
| 7th kyū | blue + stripe | orange | yellow | orange | |
| 6th kyū | yellow | green | green | purple | |
| 5th kyū | yellow + stripe | blue | purple | blue | |
| 4th kyū | green | violet | purple + stripe | green | |
| 3rd kyū | green + stripe | brown | brown | ||
| 2nd kyū | brown | brown + stripe | |||
| 1st kyū | brown + stripe | brown +2 stripes | |||
| 1st–10th dan | black +1 stripe per dan | black | |||
For Shokotan and Shitō-ryū styles, stripes are white. Shitō-ryū additionally has a 10th–15th dan, wearing a dark blue obi.
Ninja obi are required within JNF and WNF.
| Obi colour | Ninjutsu level | |
|---|---|---|
| White | ||
| Silver | ||
| Yellow | 2nd dan | |
| Orange | 2nd dan | |
| Red | ||
| Gold | 8 kyu | |
| Pale Orange | 2nd dan and 8-5 kyu | |
| Brown | 5th dan and 5 kyu | |
| Green | 2nd dan | |
| Blue, Purple | 2nd dan and 5 kyu | |
| Black | 4th dan and 10 kyu | |
| Dark Blue | 3rd dan and 10- 15-15 kyu |