Equipment Guide

Board materials

Katsura (Cercidiphyllum japonicum)

This frost-sensitive tree grows quickly to 30 meters (100 feet) in light Asian woodlands.  It prefers moist soils, and appears at elevations between 1600-2800 meters (approximately one and two miles).
(credit: wikipedia)

Producing area:

• Main island, Japan
• Hokkaido, Japan

Katsura wood produces a high quality Go board with few defects.  Some report deeper and more satisfying sound qualities than with Shin-kaya.  Katsura has a better oil content than most of the popular Go board woods today, producing complex and beautiful colors in the grain.  Supply is currently plentiful enough that it can still be made at a reasonable price.  However, compared to Genuine Kaya, Katsura lacks somewhat in brightness.

White Spruce AKA Shin-Kaya (Picea glauca var. porsildii)

A medium-sized evergreen tree growing to 15-30 m tall, rarely to 40 m tall, and with a trunk diameter of up to 1 m.   White Spruce is of major economic importance in Canada for its wood, harvested for paper-making.  It is also used to a small extent as a Christmas tree.
(credit: wikipedia)

Production area:

• North American West Coast

Hiba

Thujopsis (pronounced "Thuyopsis") is a conifer in the cypress family (Cupressaceae), the sole member of the genus being Thujopsis dolabrata.  It is endemic to Japan, where it is named Hiba or Asunaro.  Thujopsis is a medium to large evergreen tree, reaching up to 40 m tall and 1.5 m trunk diameter, with red-brown bark which peels in vertical strips.
(credit: wikipedia)

Producing area:

• North American west coast (genus Thuja)

Hiba, while difficult to work with in larger thicknesses, makes a pleasant table board.  It has a nice pale yellow color and beautiful grain.  However, it is a little soft and lacks durability compared to some other woods, such as Katsura.

Agathis AKA Shin-katsura (

While initially widespread during the Jurassic period, this conifer is now found only in small areas of the southern hemisphere.  The trees have characteristically very large trunks and little or no branching for some way up.
(credit: wikipedia)

Producing area:

• Philippines
• Indonesia
• New Guinea

Due to the scarcity of Katsura grown in Hokkaido, Agathis is sometimes used as an inexpensive replacement.  Agathis (also known sometimes as Shin-katsura) has less oil content and the hardness is not uniform.

Genuine Kaya (Torreya nucifera)

The best-known wood for Go board production, Kaya is protected in Japan because of its scarcity due to past over-cutting.  Ancient kaya trees have to die before they can be harvested to make thick kaya Go boards, which makes them extremely expensive; the finest ones can cost over $19,000.  Shin-kaya ('new kaya' in Japanese), imitation kaya, is usually Alaskan, Tibetan or Siberian White Spruce and has become somewhat popular for equipment due to the scarcity of Kaya trees. Katsura is another high-quality alternative.
(credit: wikipedia)

Production area:

• Japan (main island, Shikoku, Kyushu)
• China (Yunnan, Fujian)

Good quality Kaya material has been found in China in recent years, thus reducing the price of the scarce Japanese Kaya, the remaining examples of which are now of lower quality.

There is a story about Kaya production in the older days of the Miwa Goban shop which you may find interesting.  It goes along with this photograph...

During the 1960s after the confusion of post-war had settled, people's interest in shopping had increased.  Old-growth genuine Kaya trees were plentiful at that time.  Here you see a common example of a felled Kaya tree of that time period.  Because the trees were very big with the diameter of the trunk measuring more than 2 meters (6ft) and because of the transportation difficulties of the time, the raw timber could not even be transported back to the shop.

Thus, second generation Yasuji Miwa (second person from the left) and a lumberjack had to cut the largest part of the trunk (about 6m from the base) into smaller pieces on site, which took around one month.

In the picture, everyone is standing in front of the narrower (!!!) section of the tree (above 6m).  You can also see the 2.4m long saw next to the lumberjack on the left.  Founder Saburo Miwa can be seen in the photograph to the right of Yasuji.

Stones

For millenia, Go Stones have been made out of a broad variety of materials, including both common and semiprecious minerals.  There are many to choose from, but perhaps none have captured the imagination of Go Players like Shell & Slate.

Clamshell

During the Tokugawa Shogunate, Go stones in Japan were generally made of wood or semiprecious stones, as they were in China at the time.   The Japanese innovation of using clamshell for Go stones originated shortly after the Meiji Restoration of 1867 in the Kuwana region of Mie prefecture (then known as Mikawa).  Makers of Go equipment discovered that clamshell provided a beautiful milky white hue and delicate striations (lines) unlike any other semiprecious stone.  

The new clamshell Go Stones were instantly popular, and clam supplies in Kuwana were quickly exhausted.   At the beginning of the 1900s, most Go stone craftsmen relocated to Hyuga, whose coast had the largest and most beautiful remaining reserves of usable clamshell.   Eventually, as even Hyuga's supply was depleted, an adequate replacement was sought and found on the Mexican Pacific Coast, which saved the industry from extinction.

Today, nearly all Japanese clamshell stones are made from Mexican clams.   Stones made from Hyuga clams can still be acquired, although at astronomical prices.   Hyuga remains the center of Go stone production in Japan, and is regarded as something of a cultural treasure.

Clamshell stones are usually sorted into two categories. Jitsuyo or Hana grade have more sparse and curved striations. Yuki or "Snow" grade stones have dense, parallel striations and are chosen for superior milky-white color (although often there is no difference in color between grades).

Striations on clamshell stones are generally visible on one side of the stone, while the underside is pure white.

Slate

The tradition of Nachiguro stone, which anglophones usually call "Japanese slate", is far older than the relatively new innovation of clamshell.   It is said that Nachiguro stone has been used for black Go stones in Japan since the Nara period (710 - 794 CE).

Nachiguro was originally discovered in the valley on the upper side of the Kumano river in Mie prefecture, Japan.  It is a river-deposited sedimentary shale, the exact composition of which is unique to the area.   Remarkably, this location is less than 100 miles from Kuwano, where shell Go stones would be invented a thousand years later.   In modern times production has moved to Wakayama prefecture.

Unlike clamshell stones, Nachiguro are a solid color and are visually identical to one another.

Sizing

Go stones are available in varying thicknesses, to accomodate a player's aesthetic tastes and budget.  While the thicknesses of the stones vary, the diameter of the stones remains the same, so that they fit the board perfectly.  Most players enjoy a substantial, well rounded feel to their stones and choose the thickest set that their budget will allow.

Nachiguro are always matched to clamshell stones with an identical thickness, but with a diameter size very slightly larger than the shell stones. This compensates for the optical illusion of a black object appearing smaller than a neighboring white object.

Care and Handling

Clamshell stones should be treated with care and periodically washed with a mild solution of dishwashing detergent to remove natural oils and dirt that could eventually cause discoloration.  Always dry your stones thouroughly before using them on your Go board. Clamshell is also more delicate than slate, and if dropped from a height onto a hard surface, may chip along the striations.  If this happens, the stone should be discarded immediately to avoid damage to your Go board.

Nachiguro are usually packed with a thin layer of oil that brings out the luster of the stone.  Excess oil should be removed by gently tamping with a clean, dry cloth before playing.  Although they are more durable than clamshell, they can also be chipped if dropped.  Always discard a chipped stone to avoid damaging your Go board.

Warning: Go stones can present a grave choking hazard to young children.

Bowls

The tradition of Nagiso turnery

Just as the name would suggest, Nagiso turnery is the Japanese art of lathe-turned woodworking. Similar to the way in which a piece of pottery is made on a wheel, a piece of wood is shaped with turning gouges and chisel as it revolves. All of the work including the selection of the wood, its conversion and lacquering, and of course the actual turning, is done by an experienced craftsman, who is bent on perfecting his craft.

The quality of a country's woodwork is directly dependent on the quality of the blade tools available, which, in turn is determined by the quality of metallurgy. Since Japan's carbon steel blade tools were developed to a high level at an early date, woodwork as well was highly advanced. Whether it be a turner using a lathe to form a polished bowl or a craftsman wielding tiny chisels to carve intricate transoms, the tools used were always the best.

One of the particular merits of Nagiso turnery is the way that the work fully expresses the qualities of the wood, making the most of the natural grains in an unassuming fashion, while also retaining a handmade look, each piece making fine use of the minute variations of grain and color of the selected woods. Nagiso trays and bowls are currently being made in Japan under the guidance of 14 firms employing 131 skilled turners and others, among whom 13 are government recognized Master Craftsmen.

According to an old document found in Nagano prefecture, turnery began there sometime during the first half of the 1700s, when unfinished forms for trays and bowls were being sent to Nagoya and Osaka. For this to happen, it must be assumed that lathes were already turning sometime before.