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A is a body made of linen or Japanese paper hardened with urushi (lacquer), which allows free molding.

This technique was introduced from China and was widely used in Japan to produce Buddhist statues from the late 7th to the 8th century.
In the case of Buddhist statues, wooden cores are often used, but in the case of urushi objects, a plaster mold is made, and several layers of linen cloth are pasted onto the plaster with urushi and it’s dried and harden before being removed from the plaster mold to form a body, which is 2 to 3 mm thick.


Advantages of kanshitsu
It can be freely formed into any shape.
It does not deform like wood.
It is more durable and sustainable.

Hemp cloth does not allow the urushi to penetrate to the core of the threads, leaving the fibers of the hemp cloth, which makes a kanshistu body more robust. It rarely cracks when dropped, only chipping outside of the sabi (base layer made of urushi and sand).

Disadvantages of kanshitsu
It taks more time and is labor intensive.
It costs more because a lot of urushi is used.
It is often heavier than a wooden body.

It is a technique that allows for free ideas to be transformed into molding, but the treatment of details varies from shape to shape, and there are many occasions when new innovations are required. For trays and boxes, For trays and boxes, legs or an edge on the bottom backside made of wood would be necessary.

The body is made to be uniformly thick, so more cloth is applied or a wooden core is inserted in the part that needs to be thicker. In addition, the lid and body of the box must fit together properly, which requires a high level of skill.
For example, in the case of a box, there are several points as shown below.

Make the part that receives the lid (light blue part) and the edge on the bottom backside (pink part) out of wood and attach them to the body.

1.Thin the edge and round it.
2.Calculate the gap with the lid to be about 1 mm after completion.
3.Apply more cloth and make it a little thicker.
4.Make the part that receives the lid with wood and glue it.
5.After making and gluing the edge on the bottom backside with wood, plane and make the outside smooth along with the part of 4.

Work process

The shape of the finished vessel.

1.Draw a plan.
Draw the shape from above and another one from the side.
2.Make a sweeping mold with a plastic board.
The large circle shape seen from above is the round plastic plate at the bottom, and the curved line seen from the side is the sweeping mold.
Use a 1 mm thick plastic board for smaller vessels and a 2 mm thick plastic board for larger vessels.
A vertical thin rod stands in the center of the bottom and the sweeping mold are reinforced with wood to stabilize them.

3. Molding with plaster.
Place a large glass board on a rotating table.
Place clay or styrofoam inside so that the plaster is 2~3 cm thick.
Be careful not to wash out the plaster with a water tap.
If the shape cannot be molded with a sweeping mold, plane a plaster with a plane or carving knife, and then sandpaper to shape it.
After drying, remove the inner clay or styrofoam.
5.Apply mold release agent to the plaster mold (2 to 3 times)
After boiling glutinous rice flour and water to make a paste, add a little paint to it. (To make it easier to see if the thickness is even when colored.)
Place something in the empty space inside the plaster (the beige part of the image).

6.Apply some pastes for base layer called Jinoko-sabi (rough-grained base paste) and Tonoko-sabi (fine-grained base paste) twice each.
Do not use a brush for painting, but use a brush (horsehair) to process kanshitsu. If you do not have that type of brush, use another proper brush or a spatula.
Dry sand the surface with sandpaper to a uniform thickness.

7.Cut a piece of fine cotton cloth (#100~#110) to a size that extends 4~5 cm beyond the vessel.

8.Attach the cloth of 7.
Make a glue made from glutinous rice powder + ki-urushi + Wajima-ground powder.
Leave 1 cm of cloth over the bottom and attach it to the plaster. (After that, do not attach the protruding cloth to the plaster, but cut it off at the edge.)
After drying, cut the overlapping cloth with a carving knife.
9.Fill in the fablic
Make a glue made from glutinous rice powder + ki-urushi + Wajima-ground powder (slightly more Wajima-ground powder than for attaching the cloth) and rubbed into the recesses of the fabric with a spatula, and after it dries, it is polished dry with sandpaper.

10. Attach 3~5 sheets of coarse linen (#25~#80) in the same way as 7.~9.
Do not protrude the cloth to the bottom (the edge).
Attach 1~2 more cloths only to a part where you want more thickness.
When attaching legs or the edge of the bottom backside, attach them after applying the last layer of coarse linen.

11.Attach a piece of fine cotton cloth (#100~#110) in the same way as 7.~9.

12.Apply two coats each of Jinoko-sabi (rough-grained base paste) and Tonoko-sabi (fine-grained base paste) in this order.
13.After polishing with a whetstone, harden with ki-urushi., and after it dries and hardens, apply one coat of black urushi.

14.Remove uneven edges
Cut off any excess cloth or the base layer that has appeared below the lower portion (the edge) with a carving knife.
Then scrape the lower portion on a large flat surface sandpaper until the plaster comes out.
The portion where the cloth and the base layer appeared is then coated with several coats of ki-urushi and add Tonoko-sabi (fine-grained base paste) and waterproof it well for the process in 16.
15.Dry (harden)
In order to dry and harden the kanshitsu body and the base layer, we put it in an oven at a temperature of 100 to 130 degrees Celsius for 3 days in Kagawa Urushi Lacquerware Institute (The temperature is raised in stages).
If the inside is not firmly dried and hardened, the shape of the vessel may be distorted after it is removed from the plaster mold. If an oven is not available, to reduce this risk, ensure that each step in the process hardens one fully at a time.
For more detailed material on the baking of urushi, please refer to "Study of Traditional Baking urushi Techniques".[1] (National Research Institute for Cultural Properties, Tokyo) though it's in Japanese. However, this is not a discussion of kanshitsu but applying urushi on a metal base.

16.Soak in water for several hours and then remove the plaster mold.
In the case of trays and plates, the plaster mold can be reused because it will come off simply by applying force due to the mold release agent. For boxes, the plaster mold would be broken using a chisel, hammer, or carving knife.

17.Grind the inside of the vessel with a whetstone to a smooth surface, possibly filling it with tonoko-sabi (fine-grained base paste).
18.If the rim is to be thinned, shave it with sandpaper to adjust the thickness. If the layer of cloth is exposed, apply tonoko-sabi (fine-grained base paste) to smooth the surface and grind with a whetstone.
19.Proceed with the overall painting process to finish.

If the base layer is made thicker, the vessel becomes heavier and more prone to chipping, so proceed with each step, keeping in mind to make the thickness as uniform and thin as possible. It means that the minimum thickness is required so that the weave of the cloth will not show up weeks after completion.

Drying plaster before planing and molding.

Samples of the production process of kanshitsu by Living National Treasure, Mr. Mashiki Masumura can be viewed at Cultural Heritage Online.


1. Toshio Kinoshita, Hiroshi Ueno, Toshikatsu Nakazato, Seiko Miyata. (1998). "Study on Traditional Burnt urushi Technique". National Research Institute for Cultural Properties, Tokyo(PDF file)
2. Japan Crafts Association. "Works of Mr. Kiichiro Masumura (Living National Treasure)”. Japan Kōgei(art crafts) Association
All of them are in Japanese.

My works of kanshitsu