Beginners should always start with a bamboo Shinai. Carbon Shinai (made from plastic) are only for advanced practitioners who train seriously. The individual parts of the bamboo Shinai (see the diagram) have the same proportions as the Japanese sword. The Shinai is used like the Japanese sword and is to be treated with the same care and regard as a real sword.
There are three general Shinai sizes: 36' for children, 38' for women and young adults, 39' for men.
It is advisable to carry a reserve Shinai so that training can be continued in the practice session if some problem arises with the Shinai (the leather parts or the band may slip or the bamboo might splinter).
A wooden sword (Bokken or Bokuto) is first needed when you begin to learn Kata. As a rule, this is after the beginner has improved in basic technique training (after six months to one year).
For Kata, a wooden sword is necessary because the fine sword techniques can only be practiced with such a sword. Like a real sword, the Bokuto possesses a curved blade, tapered tip and medium grade (Shinogi). The Bokuto, in contrast to the Shinai, is very durable because the cuts and plates in the Kata are only suggested. Thus no special treatment for the Bokken is necessary.