The Saya Making Process

The saya maker chooses the wood by looking at the annual rings and grain. He then cuts a thick piece of wood to match the basic shape of the blade. This is cut in half lengthways. The exact shape of the blade is cut out of the inner sides using various chisels. Using a small knife, all of the chisel marks are removed, making the inside smooth. The two halves are rejoined using Sokui (rice glue). The two pieces are bound together using a cord with wedges inserted to increase the pressure until it is dry. *Unlike man-made chemical-based glues, sokui is kind to blades. It also has the advantage of being able to be separated and resealed easily when servicing is required.

Shirasaya

The outside of the shirasaya is finished using a plane. The saya-guchi is made to fit the handle. To hold the blade in place inside the saya, a hole is made in the handle in which a bamboo peg is inserted. The shirasaya is finally buffed using fern and elm tree leaves.

1 鞘の材料である朴(ほう)材を刀の反りに合わせて木取りをする。
First a piece of the raw materials of honoki (magnolia wood) is selected with a curvature that matches the blade’s.

2 刀のラインに合わせ木取りした材料をノコギリで正確に中割りをする。足を切らないよう注意
The selected piece of wood is cut in half lengthways using a traditional Japanese saw. The wood is held using the feet, so care must be taken not to cut one’s self.

3 鑿(のみ)やナイフを使い刀の形に合わせ彫り込む。これを「掻(か)き入れ」と言う。掻き入れは接着すれば見えなくなるので手抜きをする人や、簡単に考えがちだが、実は鞘を作る上で最も重要な工程である。刀を錆させたりしないための工夫と技術が凝縮されており、訓練を重ねなければ絶対に出来ない。こうした目に見えないところを完璧に仕上げることは職人にとって大切な考え方である

The outline shape of the blade is carved into the wood using a chisel or a knife. This process is called kakiire. Because the rejoining of the two half’s should not be seen, people not doing by hand think simply, actually, this is the most important point in scabbard (saya) making. In order to protect the blade from rust, one must use the correct skills and devices. If the correct training is not taken, you absolutely cannot make an effective saya for a Japanese sword. The construction of a completed saya with a join that cannot be seen, is most important in the craftsman’s thought.

4 続飯((そくい)お米を練って作った糊)を作り、掻き入れをした鞘を接着する。*しっかりと紐で固定し鞘を接着させる

Sokui is a natural glue made from rice. It is applied to the two carved out half’s of the saya, and the saya is firmly bound together using a cord.

5 鉋(かんな)で削りだす前に、鯉口を、おおよそ出来上がりの形に口取りをする 白鞘と拵えはここから工程が変わる 今回は白鞘工程とする

Using a Japanese wood-plane (kanna), the opening (koi-guchi) of the saya is finished, from this point onwards the processes differ according to the production of a shirasaya (plain wooden sleeping scabbard), or one to used fro mounting. This is the process for shirasaya.
6 8角の鞘に正確に削る 最初から丸く削ると基準となるラインを見失うので正確な8角の基準を削り出す
The saya must be shaped with 8 precise corners. First it is shaped into an oval shape, then as the guidelines are removed, it must become a precise oval octagonal shape.

7 基準となる8角を基に鞘に丸みを出す為、平、刃棟 側面と削る 肉置きというのは、丸みのことであり、削りながら丸みお出すのは非常に繊細な作業である。 削りの最終作業
Once the lines are correct, the hira, ha-mune, sides, are planed, the meat (niku-oki) of the saya can be rounded, this process is a very delicate task. This is the last process of planing.

8 鯉口を隙間なく鉋で合わせる

The koi-guchi is planed to meet the tsuka with no gaps.
9 目釘穴をあける
The mekugi-ana (retaining peg-hole) is made.

10 研草(トクサ)にて磨きの作業
Using natural bamboo grass called tokusa, the outside of the saya is polished.
11 丸みがあり、鎬筋をはっきり出し鞘本来の美しい光沢を出すのはトクサでなければならない これは紙ヤスリで仕上げる倍以上の訓練と技術が必要である  *紙ヤスリでも磨けるが、木の目にヤスリの粉が入り、鎬筋がはっきりせず、独特な仕上がりとなる  紙ヤスリは金剛砂が飛び散り刀身に細かいキズやヒケをつける原因となるのでやはり天然ヤスリのトクサが良い
the rounded saya has all of its lines straight,should have a luster brought out by the tokusa. This job requires more than just sand paper, it requires special training. If you use sandpaper, the scratches enter the grain of the wood, and the lines of the saya will not be clear. It is a special finishing . Fine grains from sandpaper causes scratches and hike in blades, so natural resources like Tokusa are best.

Koshirae

In the case of a scabbard that is made for a koshirae, the thickness of the lacquer must also be taken into consideration. Saya made for koshirae must be thinner than those made for shirasaya. Here the buffalo horn koi-guchi, kurikata, kaeritsuno, and the kojiri are attached. The mountings are now passed to the lacquerer and the handle wrapper.