Sageo is the cord used on the scabbard (Saya) of a Japanese Katana. Sageo in Japanese is "下緒", literally means "Hanging cord". Because the main purpose of Sageo is to tie the katana to the belt (Obi). Sageo passed through the Kurigata of the Saya, comes in multiple colors, styles, lengths, and designs. The sageo itself can be made from silk, cord, leather etc. It is generally good form for the sageo color to match the tsuka-ito color (handle wrapping).
How long is Sageo? Common length for Sageo ranges from 120 - 240 cm ( 47 to 94 inches), usually 120 cm (47 inches) for Wakizashi and 220 cm (87 inches) for Katana. In modern days, there are no set rules for the Sageo length, it can be customized based on different swordsmen style and personal preference.
Tying a Ronin Musubi 浪人結び Ronin Musubi is known as Masterless Samurai or Swordsman Knot. This is a decorative type of braided cord. Make a knot Make knots again and again Pass the cord through the knots. Fix the shape.