囲碁将棋盤 榧寿堂 ／ Why Two Hon-kaya Go Boards Can Differ So Much in Price: Grain Cut, Thickness, Origin and Flaws
Why Two Hon-kaya Go Boards Can Differ So Much in Price: Grain Cut, Thickness, Origin and Flaws
Browse a Japanese shop for a real kaya go board (hon-kaya, 本榧) and the first thing you notice is the spread. Two boards of the same wood and the same playing surface can sit next to each other with very different prices.
The species is only the starting point. The price comes from a set of things Japanese board makers grade one by one: how the board was cut from the log, how thick it is, where the tree grew, and how clean the surface is. This page goes through each, using what the board makers themselves publish, so that a listing written in Japanese starts to make sense.
We have left out yen amounts on purpose. Prices for kaya boards are set board by board, so the useful thing is to know what you are paying for, then ask the shop for a quote.
The short version
- Grain cut (kidori, 木取り) matters most. Straight-grain boards (masame, 柾目) need a very old, very large log.
- Thickness, counted in sun (寸, about 3.03 cm). The thicker the board, the larger the log it came from.
- Origin. Kaya from Hyūga (日向, present-day Miyazaki Prefecture) is the name you will see on the most valued boards.
- Surface quality: knots, cracks, stains, pale sapwood, uneven colour. Each one lowers the grade.
- One-piece or joined. A joined board costs less, and Japanese makers say it plays much the same.
1. The grain cut (kidori)
Kidori means how the board was taken from the log, and it is the single biggest reason two kaya boards differ in price.
Straight grain (masame) and flat grain (itame)
- Masame (柾目, straight grain): the growth rings stand close to upright against the playing surface, so the top shows parallel straight lines.
- Itame (板目, flat grain): the rings lie closer to flat, and the top shows arches or waves.
A straight-grain board has to come from the part of the log between the core and the bark. Maekawa Kaya Goban-ten, a kaya board specialist, says masame 「丸太の半径部分からしか取れないため、樹齢の高い大木からしか作ることができない」 (“can only be taken from the radius of the log, so it can only be made from a large, old tree”). Maruhachi Goban-ten, a board maker, puts a number on it: a masame board needs kaya 「少なくとも樹齢400年以上」 (“at least 400 years old”), because the sapwood and the core can’t be used (Maekawa, “How to choose go and shogi boards”; Maruhachi Goban-ten, “Kidori”, both checked Oct 28, 2026).
That is the core of the price gap: a log big enough for a straight-grain board is rare.
The masame family: tenmasa, tenchimasa, shihomasa
Straight-grain boards are graded again by what the grain does on the sides.
| Term | What it means |
|---|---|
| Tenmasa (天柾) | A line drawn out from the core becomes the playing surface, so the grain meets the surface at right angles throughout. The top and the underside are clearly different |
| Tenchimasa (天地柾) | On the end faces, the straight grain runs all the way from the top to the underside; the left and right sides (koba) show flat grain |
| Shihomasa (四方柾) | Straight grain on all four faces: top, bottom, left and right. It needs a very large log |
| Oimasa (追柾) | Between straight grain and flat grain |
Maruhachi says of tenchimasa that 「木端（こば）は両方ともに完全な板目になる」 (both side faces are fully flat grain), and that a true shihomasa is prized, though 「実際は追柾を四方柾と錯覚している場合が殆どです」 (“in practice most are oimasa mistaken for shihomasa”) (Maruhachi, checked Oct 28, 2026).
Which cut ranks highest depends on the shop
Japanese shops do not all rank these the same way. Maekawa lists them 「高級な順に」 (from the most valued): shihomasa, tenchimasa, tenmasa, then oimasa, then the flat-grain boards kiura and kiomote (Maekawa). Maruhachi calls tenmasa 「面の美しさを重視した最高の木取り」 (“the finest cut for the beauty of the surface”) (Maruhachi).
So read “highest-grade cut” in a listing as that shop’s view, and ask which cut it actually is.
Flat grain: kiura above kiomote
Flat-grain boards come in two kinds, depending on which side of the plank faces up.
- Kiura (木裏): the playing surface faces the core side of the tree.
- Kiomote (木表): the playing surface faces the bark side.
Maruhachi says a kiomote board is seen as 「木裏面よりランクが下」 (ranked below kiura), and in Maekawa’s list kiomote comes last. For a fuller guide to reading grain, see our guide to go board wood grain.
2. Thickness
Japanese boards are sold by thickness in sun (寸). One sun is about 3.03 cm, so a 5-sun board is about 15 cm thick and a 6-sun board about 18 cm.
A thicker board needs a bigger log, and the price follows. Maekawa’s guide to legged boards (ashitsuki-ban, 足付盤) describes the steps (Maekawa, checked Oct 28, 2026):
| Thickness | Maekawa’s description (summary) |
|---|---|
| 3 to 4 sun | Thin for a legged board; from 4 sun the sound, presence and beauty reach a level for serious players |
| 5 to 6 sun | 「実用性と格調のバランスが最も良く、足付盤の中で最も人気が高い厚さです。」 The best balance of practicality and dignity, and the most popular thickness. Boards over 6 sun are treated as more valuable |
| Over 7 sun | 「圧倒的な風格と存在感を放つ超高級品」 Top-end boards with overwhelming presence. Very heavy: some exceed 30 kg |
Thickness is also where weight and your room come in. A thick legged board is a piece of furniture you will not move often. For how thickness sets the weight, see How Heavy Is a Go Board?.
3. Origin
Japanese listings often name where the kaya grew. The name you will see on the most valued boards is Hyūga kaya (日向榧), kaya from the old province of Hyūga in present-day Miyazaki Prefecture, Kyushu.
Part of the reason is scarcity. Maruhachi writes that the city of Miyazaki, concerned that kaya timber is running out, has started a project to plant Hyūga kaya, but that it will take 500 years before those trees can be used for boards: 「盤材として使用できるまでには500年の歳月がかかるそうです」 (Maruhachi, checked Oct 28, 2026).
When a listing just says hon-kaya, it tells you the species, and the origin is a separate question to put to the shop.
Shin-kaya (新榧) is a different matter: despite the name, it is not kaya. Maekawa describes it as 「本榧とは別物の北米から輸入されるスプルース材」 (a spruce imported from North America, a different thing from hon-kaya), whitish in colour, with a shorter working life (Maekawa). It is the main reason a “kaya” board can look surprisingly cheap. More on the difference in What Is Kaya?.
4. The surface: flaws, colour and fine grain
Two boards with the same cut, thickness and origin can still be priced apart, and this is why.
Flaws
Maekawa: 「天然木であるため完全に無傷なものは稀ですが、欠点がない、あるいは目立たないものほど高価値になります。」 (“As natural wood, a completely flawless board is rare, but the fewer and less visible the flaws, the higher the value.”) The flaws it names (Maekawa, checked Oct 28, 2026):
| Japanese | Meaning |
|---|---|
| フシ (fushi) | Knots |
| 割れ (ware) | Cracks |
| 入り皮 (irikawa) | Bark caught inside the wood |
| キズ (kizu) | Scratches and dents |
| シミ (shimi) | Stains |
| シラタ (shirata) | Pale sapwood from near the bark |
Colour and lustre
Even colour with no blotches is preferred, along with natural colour and an oily sheen. Maekawa adds that hon-kaya in particular 「経年変化で美しい飴色の光沢が増していきます」 (deepens to a beautiful amber lustre over the years).
Fine, even grain
Maekawa again: 「木目が細かく詰まっているものは、樹齢300〜400年以上の大木からしか取れないため、最良とされます。」 Tightly packed fine grain only comes from trees of 300 to 400 years or more, and is considered best. Straight, evenly spaced lines rate higher.
Grade labels in listings
Some shops put all of this into a grade name. Kyoto Ōishi Tengudō, a long-established Kyoto maker, describes its scale like this (Kyoto Ōishi Tengudō, “Reading grades and size labels on go and shogi boards”, checked Oct 28, 2026):
- Tokujō (特上): 「材質としては最高の条件を備えております。」 The best possible material.
- Jō / Matsu (上・松): 「ほぼ欠点のない美麗品です。」 A fine board with almost no flaws.
- Chū / Take (中・竹): 「多少シミ、フシなどの難があります。」 Some stains, knots or similar.
- Nami / Ume (並・梅): there are flaws somewhere.
These names belong to each shop. Use them to compare boards within one shop, and ask for photos when comparing across shops.
5. One-piece or joined
A board cut from a single piece of timber is ichimai-ita (一枚板). A board made from several pieces glued side by side is a joined board, hagi-ban (接ぎ盤). Maekawa says a joined board is easier to source and so can be priced lower, and that 「一枚板と比べても、打ち味や打音、耐久性などに大きな違いはありません。」 (compared with a one-piece board, there is no great difference in feel, sound or durability) (Maekawa).
What you pay for in a one-piece board is the unbroken grain. More on one-piece and joined go boards.
Putting it together: where to spend
| What you want | Where the money goes |
|---|---|
| Real kaya to play on, sensible budget | Flat grain (kiura), a modest thickness, or a joined board |
| A board to keep for a lifetime | A legged board around 5 to 6 sun, then a straight-grain cut as budget allows |
| The board as a piece of craft | Straight grain on more faces, Hyūga origin, few or no flaws |
If hon-kaya is beyond your budget, see Go Board Woods Beyond Kaya.
What to ask the shop before ordering from Japan
Copy these into your message:
- Wood: hon-kaya or shin-kaya? If hon-kaya, where did it grow?
- Cut: masame (which: tenmasa, tenchimasa, shihomasa) or itame (kiura or kiomote)?
- Construction: one-piece or joined?
- Measured size: thickness in cm, total height with legs, weight in kg.
- Flaws: any knots, cracks, stains or sapwood? Photos of all six faces in daylight, please.
- Grade: which grade name, on that shop’s scale?
Once the board arrives, keep it out of direct sun, away from heaters and air-conditioning drafts and places where wind blows straight across it, and avoid shutting it away where humidity builds up. See our guide to caring for a go board.
Common questions
Is a more expensive kaya board better to play on? Not always in proportion. Much of the price is about the look of the grain and the rarity of the log. Maekawa says a joined board plays much like a one-piece board, and a flat-grain board is still kaya.
Is straight grain always the top grade? Straight grain is valued above flat grain, but which straight-grain cut is “best” depends on the shop: Maekawa puts shihomasa first, Maruhachi calls tenmasa the finest cut.
Why is shin-kaya so much cheaper? Because it is a different wood, a spruce imported from North America. Its working life is said to be shorter.
How do I know where the kaya came from? Ask the shop. A listing that says only hon-kaya names the species, and the origin is a separate question.
Summary
- The price of a kaya go board comes from cut, thickness, origin and surface quality, all at once.
- Straight grain needs a log of 400 years or more (Maruhachi), which is why it costs more.
- Over 6 sun, legged boards are treated as more valuable, and some thick boards exceed 30 kg.
- Flaws and grade labels explain the gaps between otherwise similar boards.
- A joined board plays much the same as a one-piece board.
All quotations were checked on the named shops’ pages on October 28, 2026.