What is fukusa in Japanese Katana terminology?

"袱紗" or "fukusa" translates to "Cloth Wrapper" in English. It is a type of cloth used when appreciating Japanese swords. The cloth is held in the left hand to support the blade of the sword, preventing direct contact between the hand and the blade. This is done to protect the blade from oils and dirt that could be present on the hand, which could potentially damage or tarnish the blade. The cloth wrapper also provides a safe way to handle the sword during the appreciation process.