Saja

Saja, scabbard, swords sheath. Its purpose is to protect the blade from outer influences while sword is not being used. It is made of magnolia wood. But in our conditions we can use alder wood, eventually linden. These are soft wood, which do not content resins or aggressive oils which could harm the blade. The wood must be of course well dried. You need couple of tools for making saja. Saw, Japanese saws (Ryoba) are the best. Comparing to the European tools the Japanese saws are being used in direction towards the user. Ryoba saw has reversed toothing that allows clear and accurate cut. Then you need some chisels. Also with specific shape that allows chiselling below the current material surface level. To shape the surface you need beading planes. The chisels and beading planes blades are made of similar material to the swords blades. Tool maintenance and sharping must be done with proper look out. That allows much easier and precise work.

First of all you need to select the wood. This is then sliced up into desks. It must be without flaws, cracks, knags and dry-rot. The desk you pick is planed. After that you put the blade on it and encircle it by pencil. This silhouette is then trimmed by knife. Saja is made of two halves. Both are a bit different. One has about 1-1,5 mm recessing on the edge side that is this way not placed against the glued joint (it is harder). This creates a bit of space that allows drawing the sword without any difficulties (wood works with changing surroundings in dependence on temperature and humidity).

So the cut on the edge side goes 1,5 mm deep and on the back side to approximately 1 width of the back of the blade deep. Then you do the chiselling. The shape of the mortise hole copies the blades profile, but not its planes. The plane between the edge and the back has inside the saja shape of a lens, for the blades with shinogi (rib) too. This lens is always bulging a bit more than the blade itself. The blade placed in the mortise hole must only touch the wood by the edge and at the edge of the back. There is a tiny space between the blade and saja. It is for the blade not being scratched by the sides of saja while drawing and putting back in.

Second side has no recessing by the edge. The surface of the mortise hole must be cleaned after chiselling (if necessary). Abrasive papers are not good for such cleaning because of the pieces of abrasives that remains cut in the wood. Those would cause scratches on the blade. So it is better to use steel rules. If the mortise hole is done well by sharp tools, there will be no cleaning necessary. After that you only slope the back and correct the mouth of the sheath according to habaki. Then you put both halves together, try whether the blade goes smoothly and if everything is all right (the blade can be drawn and put back without any sign of resistance) you will glue them. The traditional way is rice glue - boiled rice is after two days boiled to mush and final substance is spread by spittle into pasta. We can use classic dispersive glue for the wood. It is good to draw the position of the blade on the outer side of saja before gluing. Only very thin layer is needed. The glue must not get in the space inside saja. It is necessary to be very careful with this step. After connecting both sides try to put the blade inside again. After the glue gets dry we continue shaping the saja. First of all we use beading plane to create curvature of the back and the edge. Then we take away surplus material from the sides up to the required thickness of the saja. Then we use beading plane again to create octagon and it is farther dressed until saja has oval profile. The better and sharper tools you use for this step, the better product you get. Sharp beading plane can create almost clean and plain surface. Blunt tools make the work much more difficult.

Next step is placing the components on the saja - koiguchi (mouth), kurigata, kojiri (top of the saja) eventually kaerizuno (back hook). We use a sharp knife to cut a recessing at the mouth (see the picture). It is good to create a recess also for kurigata. If kurigata is only glued to the surface it will be easy to break it while using. It is necessary to hollow out a space for little knife - kogatana and needle - kogai if they are parts of the set. You must be very careful and precise. You must not cut through the sides into the space for the blade.

The components are made of black keratin, eventually of metal (the same as fuchi on the handle). The keratin is well workable. You cut out the future shape of the component, use files and abrasive paper to shape it into the final form and polish it. Work with metal component is similar, but metal is not as well workable as keratin. Components are better to be placed after lacquer finishing except kurigata. You place several layers of lacquer until it is thick enough. As soon as it gets hard we whet it and polish it. Traditional way is using Urushi (Japanese kinnikinic resin), but it is also possible to use todays lacquers – epoxy etc. After finishing the lacquer we place and glue the components to their places. We can also place sitodome into the opening in kurigata (decorative metal component). With that we pull sageo through this opening and saja is finished.

The surface on the lacquer can be glossy, dim, soft or rough structured (less inclinable to damage). It is also possible to create various periodic structures in the lacquer as kizami (ribbing) for example. Another option is gluing little bits of nacre on a thin layer of lacquer. Spaces between them are filled by lacquer and as soon as it gets hard it is repolished. Similar alternative is coating saja by same (ray skin) and further lacquering it and brushing it. That creates very attractive pattern (white ringlets). There is another separate version – shira saja – handle and scabbard are made of only dressed and lacquered wood with no farther decoration. Its profile can be oval, octagon and others. It can only have keratin koiguchi and fuchi and little keratin square around mekugiata (opening for mekugi). On shira saja are usually written data and descriptions about the blade it is made for. It is designed for storing the blade only. It is not meant to be used in battle or for practice.