of wear became the standard for wearing kimono both inside and outside, evolving into the hip fold worn today. Nowadays the 's only function is decorative. It is part of a 7-year-old girl's outfit for celebration of Shichi-Go-San. (pre-tied ) are popular as children's because of their ease of use. There are even formal available for children. These correspond to on the formality scale. In martial arts Many Japanese martial arts feature an as part of their uniform. These are often made of thick cotton and are about wide. The martial arts are most often worn in the style; in practice where the is worn, the is tied in other ways. In many martial arts the colour of the signifies the wearer's skill level. Usually the colours start from the beginner's white and end in the advanced black, or masters' red and white. When the exercise outfit includes a , the colour of the has no significance. Knots () The knot tied with the is known as the . Though functioned to hold the kimono closed for many centuries, beginning in the Edo period, the became too wide and/or too stiff to function effectively in this manner. In the modern day, a number of ties and accessories are used to keep the kimono in place, with the functioning in a more decorative capacity. Though most styles of can be tied by oneself, some varieties of formal women's can be difficult to tie successfully without the assistance of others. There are hundreds of decorative knots, particularly for women, often named for their resemblance to flowers, animals and birds. knots follow the same rough conventions of style and suitability as kimono do, with the more complex and fanciful knots reserved for younger women on festive occasions, and knots with a plainer appearance being mostly worn by older women; however, some knots, such as the , have become the standard knot for women of all ages, excluding young girls. In earlier days, the knots were believed to banish malicious spirits. Many knots have a name with an auspicious double meaning. Types of knots is a knot resembling the Japanese morning glory, suitable to be worn with . The knot requires a very long , so it can be usually only be made for little girls. is a very complex and decorative knot resembling an iris blossom. It is considered suitable for young women