Saya construction

The saya is the scabbard of a sword in Japanese. The saya has a beautiful finish to it and is very often so highly lacquered that one might think it was plastic! It is, in fact, traditionally made from magnolia (ho) which is easy to work, has very little sap and is said to have oils wihtin it to help preserve the blade (An introduction to japanese Swords, I. Bottomley). 

I found a very interesting website outlining the main processes of making a saya:

• Kidori & Nakadoshi: Cutting & Splitting the Blank
• Kezuri-awase: Planing the Inner Surface
• Kaki-ire: Chiseling the Space for the Blade
• Norizuke: Gluing the Two Halves Together
• Arakezuri & Nakakezuri: Rough & Fine Planing the Outside
• Mekugi-ana-age: Drilling the Rivet Hole
• Shiagekezuri & Shiagemigaki: Finish Planing & Finish Polishing

Usually the hilt (tsuka) is also made from magnolia wood. I believe the ho wood is cut from the Japanese magnolia or Magnolia hypoleuca (possibly Magnolia liliiflora).

The saya is an important part of the sword in iai. Correct usage of the saya helps the drawing of the sword rendering the iai-to a two part weapon: sword and saya.