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| Source: JAPAN TRADITIOANL CRAFTS AOYAMA SQUARE |
Osaka Naniwa Tinware, a traditional
Japanese craft made from tin
Characteristics of Osaka Naniwa Tinware
Osaka Naniwa Tinware is metalwork made in
the area around Osaka City, Osaka Prefecture. Using the metal tin as a raw
material, a variety of products are made, including Japanese and Western-style
sake cups, tea sets, flower vases, and other vessels, as well as sacred objects
and Buddhist ritual objects. In 1983, tin was selected as a traditional craft
designated by the Minister of Economy, Trade and Industry.
Tin is one of the materials that have been
used by mankind since B.C. It was brought to Japan around the 6th to 7th
century. Tin necklaces and bracelets have been found as burial accessories in
ancient tombs, and tin vases and water bottles have been preserved in the
Shosoin Imperial Treasure. Tinware was apparently used only for court
vessels and Shinto ritual utensils such as sake cups and sakaki stands at
shrines. In particular, most of the tokuri were made of tin, and even today,
people still refer to sake as “osuzu” in the court tradition. In the
Edo period (1603-1867), as tinware became more commonly used, Osaka began to
manufacture and sell tinware, and gradually grew into a major production
center. Today, Osaka Naniwa Tinware accounts for 70% of the national market
share.
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| Source: Osaka Suzuki Corp. |
Attractiveness of Tin
Rust-resistant, stable metal
Tin is known as an extremely rust-resistant
metal. This does not mean that it does not rust at all, but it does mean that
it oxidizes very slowly. Rust is caused by a change in the metal’s
composition when it combines with oxygen in the air, but tin itself is stable
and does not easily combine with oxygen. Unless you do something to encourage
rusting, there is no visible change in the appearance of tin when used in daily
life. Therefore, since there is little discoloration, the beautiful luster can
be enjoyed for a long time.
However, as it is used more and more, the
surface luster will soften and take on a unique antique-like texture. This
gives it a moist and calm atmosphere, which is also very tasteful. Some people
prefer this atmosphere, but if you are concerned that the surface looks cloudy,
you can restore the original luster by rubbing it with a cloth or melamine
sponge dipped in baking soda.
Antibacterial action
It has long been said that if a tin plate
is submerged at the bottom of a well, the water will stay clean, and that
flowers in a tin vase will last longer. This is due to the ionic effect of tin. The
tin ions suppress the growth of bacteria in the water and purify the water in
the well, so the cut ends of cut flowers are free of bacteria.
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| Source: TAKASHIMAYA Online Store |
History of Osaka Naniwa Tinware
The origin of tinware production in Osaka
is recorded in “Namba Jakku” in 1679 (Enpo 7) as “Tinpiki, Sakai
Isuji.” In the mid-Edo period, tinware was produced in Kamigata (Osaka)
where distribution was good, such as Shinsaibashi, Tenjinbashi and Tennoji, and
eventually expanded from a production center to an industry.
The long-established tin shop “Tin
Han” (closed in 1996) opened in Shinsaibashi, Osaka in 1714 (Shotoku 4). Many
Osaka tinware makers gathered there and established the status of tinware as a
specialty product. During its heyday in the first half of the Showa period
(1926-1989), it is said that more than 300 craftsmen competed with each other
to produce tinware in Osaka. However, with the outbreak of World War II, Osaka
was hit hard by a succession of call-outs of craftsmen and difficulties in obtaining
materials due to wartime restrictions. Nevertheless, in March 1983, as a result
of deliberations on the traditions, techniques, and skills of tinware, the then
Minister of International Trade and Industry (now Minister of Economy, Trade
and Industry) designated and approved it as “Osaka Naniwa Tinware,” a
traditional craft.
Production Method & Process
1. Raw materials
Tin is the metal used. Tin ore used to be
mined in Japan, but since the 1950s, tin mines have been closed one after
another, and in recent years, tin is imported from Thailand, Malaysia,
Indonesia, and other countries. Osaka Naniwa Tinware uses an alloy of at least
97% tin (3% lead) as raw material.
2. Casting Process
Tin has a low melting temperature of
approximately 230°C, so it can be easily melted using city gas. Tin ingots are
melted in a pot, and the liquid tin (called hot water) is poured with a ladle
into a mold made of cement, clay, or metal. If the temperature of the mold is
too low at this time, the poured hot water will harden quickly, so the mold is
heated to the proper temperature over time by repeatedly pouring hot water into
the mold and returning it to the pot or dipping it in the hot water from the
pot.
The best time to remove the mold is not
after it has hardened completely, but just before it begins to solidify and
shrink, since the tinware is cast without breaking the mold. The glowing water
begins to turn white at 186°C, the eutectic point of tin and lead, and this is
the right time to remove the mold, but it is not obvious from outside the mold.
If it is too early, the product may lose its shape, and if it is too late and
cools down too much, it may not come off without force and break the mold, so
the craftsman’s experience is the key to success. Once removed from the mold,
excess tin protruding from the spout is cut away.
3. Cutting process
The round shape is cut and shaped using a
potter’s wheel. Since tin casting cannot be made thin-walled, the mold is made
to be 50% to twice as thick as the product. Tea caddies, for example, are
formed into a good shape thanks to the skill of the craftsman who precisely
aligns the lid and the mouth of the casing here. For long and slender items
such as vases, or items that cannot be cast in a single mold, the upper and
lower parts are cast separately, and the inner and outer surfaces are cut and
joined together to finish the product. At this time, several planes are used
for different purposes, such as scraping off rough casting surfaces, shaping,
and finishing. Sometimes, the traditional materials such as “tokusa”
and “muku-no-ha” are also used to bring out the luster.
4. Middle Work
This is the process of attaching accessory
parts such as handles and spouts that cannot be made on the potter’s wheel.
This process includes cutting, bending, and tapping to create a hammered
pattern.
5. Pattern-application process
Patterns (pictures) are added using lacquer
or enamel to the finished product on the potter’s wheel. When the pot is dipped
in nitric acid solution, only the other parts of the pot will be corroded and
become nashiji (a ground pattern of fine irregular bumps and dents). After
checking the relief of the pattern, the pot is rinsed with water and repeatedly
coated with black or vermilion lacquer and then wiped, and the pattern shines
and rises to the surface. This is a delicate process in which the degree of
corrosion varies depending on the season.
6. Finishing process
After the lacquer has dried, the pot is
then turned on a potter’s wheel again to bring out its luster, and handles and
other parts are attached.
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| Source: JAPAN TRADITIOANL CRAFTS AOYAMA SQUARE |
Summary
Tin has a large ionic effect and is said to
purify water. It is also airtight, which has led to the production of sake cups
and water bottles that mellow the taste of sake and water, as well as tea
caddies for storing tea leaves, and other products designed for ease of use. In
addition, plates, vases, and tea saucers that took advantage of the beautiful
luster and unique texture of tinware came to be made and used in restaurants in
Osaka and Kyoto. Thus, tinware, as a luxury vessel, spread to ordinary
households.
