Tsukamaki is the traditional art of wrapping the grips of Japanese swords. These wraps can be basic or very intricate, but the basic form of the wrap is easily recognized and contributes substantially to the classic appearance of Japanese swords. Mastering traditional tsukamaki takes years of practice, but basic simplified versions that explain how to wrap a samurai sword handle are not terribly difficult to do.
Place the midpoint of the ito against the unwrapped hilt, perpendicular to it and flat against the metal collar just underneath the guard. The ito should be on the side of the hilt that faces outward when the sword is worn.
Pull the ito tightly and evenly around the hilt to the other side and flip the sword over. Where the two halves of the ito cross one another, twist one half over twice, giving it a slight S-shape, and then do the same with the other half so that the two halves of the ito form an X-shape in the center of the hilt. Pull the two halves tightly and adjust them so that they both lay flat against the hilt on either side of the X-shape.
Flip the sword over again and repeat the process on the original side. This time, reverse which half of the ito you twist and lay down first; if you made the first X-shape with the left half over the right half, for example, form this one with the right half over the left.
Repeat this process all the way down the length of the hilt. Remember to keep the ito pulled tightly on both sides, and adjust each wrap as you finish it so that there is no gap between it and the wrap above it. The wrap should create a diamond pattern down the flat sides of the hilt and completely cover the thin sides.
Tie a knot to secure the wrap when you reach the end of the hilt. For a traditional knot, thread one side of the ito under the last X-shape so that it points toward the end of the hilt. Thread the other side of the ito over and around around the first, then under the same X-shape in the opposite direction. Fold this side and thread it back under the X-shape and under itself so that both halves point toward the end of the hilt. Wrap both halves side-by-side over the hilt end, and thread the folded half underneath the last X-shape on this side. Cut the remainder of this half off, leaving just enough to wrap over the X-shape and tuck the end back under. Do this, and glue the end in place. Thread the other half under the X-shape, then fold it back and thread it under again, crossing the other half as you do so. Lastly, cut off the remainder of this half, leaving just enough to wrap over both sides horizontally and tuck the end under the X-shape. Do this, and glue the end in place.