囲碁将棋盤 榧寿堂 ／ One-Piece or Joined Go Board (Ichimai-ita vs Hagi-ban): Where the Price Gap Comes From, and What It Changes at the Board
One-Piece or Joined Go Board (Ichimai-ita vs Hagi-ban): Where the Price Gap Comes From, and What It Changes at the Board
When you compare Japanese go boards, you will sometimes find two listings that both say “kaya, so many sun thick”, yet one costs several times the other.
One reason is construction: whether the board is ichimai-ita (one piece, cut whole from a single log) or hagi-ban (joined from several boards side by side). People tend to look only at the wood and the thickness, but this difference moves the price a great deal.
This page sets out what actually differs between the two, how much of that difference you notice when you play, and where the dividing line falls when you choose.
The short version
- The price gap comes not from the extra work, but from how rare a log is that can yield the whole board in one piece.
- The sound and feel of play depend mainly on the wood and the thickness. A joined board is not a worse board for playing on.
- What a one-piece board buys you is rarity, continuous grain and value as a keepsake, not playing performance.
- Warping and cracking depend more on where and how the board is kept than on how it was built.
- For a board to play on, a joined board is enough. Put the money saved into thickness or stones.
1. How the two are made
| One piece (ichimai-ita) | Joined (hagi-ban) | |
|---|---|---|
| Construction | Cut whole from one log | Several boards joined edge to edge to make the width |
| Log needed | A log big enough for the full width and thickness at once | Narrower timber will do |
| Price | High: the rarity of the timber goes straight into the price | Lower |
| Playing surface | No joints | Joint lines visible (on well-made boards, barely) |
Maekawa Kaya Goban-ten, a Japanese board maker, describes a joined board as made from about two to five pieces of wood joined side by side, easier to source and lower in price.
The real source of the price gap is the rarity of the log, more than the labour.
A go board is a large, nearly square slab. To cut it in one piece, you need a log wider than the board. For a slow-growing wood like kaya, where large trees are already scarce, that is very hard to find, so “one piece” means “rare” almost by definition. Within one-piece boards, Maekawa notes that quarter-sawn (masame) boards can only come from old, large logs, which is why they are especially valued.
Where kaya itself stands is covered in Honkaya vs Shinkaya.
2. Does it play differently?
This is the point worth being clear about.
The sound and feel of stones on the board are shaped mainly by the species of wood and the thickness (sun). You cannot say that a joined board sounds bad simply because it is joined. Maekawa states it directly: compared with a one-piece board, a joined board shows no great difference in feel, sound or durability.
Same wood, same thickness: a joined board can play beautifully. In practice, joined boards are widely used as everyday boards.
How thickness changes the feel is covered in Go & Shogi Board Thickness. On a limited budget, a thick joined board will often satisfy you more than a thin one-piece board.
3. So what does a one-piece board buy?
Mainly three things:
- Rarity in itself: a whole board from one large log is uncommon
- Continuous grain: no joints, one unbroken surface
- A keepsake: suited to a commemorative gift or a board kept for a lifetime
Put the other way round, a one-piece board does not buy you better play. Mixing the two up is how budgets get spent in the wrong place.
The way the board is cut from the log (the grain: masame, oimasa, itame) also moves the price of one-piece boards a great deal; see How to Choose a Go Board.
4. Which warps or cracks less?
You will hear both “one-piece boards crack” and “joined boards open at the seams”. Neither construction clearly wins.
- Given Maekawa’s statement that durability does not differ greatly, it is not safe to claim that one-piece boards warp more, or that joined boards are more stable.
- What to watch on a joined board is the condition of the joints after many years.
Either way, what decides it is where the board lives and the humidity. Keep it out of direct sunlight, away from heaters and air-conditioner draughts, and out of places where wind blows straight through; that matters more than the construction.
This is especially important if your board has travelled from Japan to a very different climate, such as dry winter heating or a humid summer. Sort out where the board will live before worrying about how it was built.
5. Choosing: where the line falls
A joined board is enough when
- you are buying it to play on (often, perhaps with family or students)
- you want as much thickness as the budget allows
- the room it will live in is not ideal
Choose a joined board with confidence. Put what you save into thickness or into stones; see How to Choose Go Stones.
A one-piece board makes sense when
- it is a keepsake or a gift for a milestone
- you value the look of continuous grain
- you can give it the right place and care
- you may pass it on one day
Do not let “I want a good board” turn automatically into “I want a one-piece board”. Decide what the board is for, and the choice mostly makes itself.
6. Buying second-hand
Second-hand listings often do not say whether a board is one-piece or joined.
The surface, the grain on the ends (kiguchi), and whether there are joints are hard to judge without seeing the board. Do not rely on the description alone. If you cannot see it in person, at least ask for photos of both ends, both sides and the underside.
FAQ
Will I notice the joints when I play? On a well-made board, hardly at all. Most people stop noticing once they are used to the lines and grain. It is personal, so look at one in person if you can.
Does the number of pieces matter? It is one of the factors behind the price, but the feel is not decided by the number of pieces. The quality of the wood and the thickness matter more.
If a board is one piece, is it kaya? No. Construction and species are separate questions. One-piece boards exist in katsura, shin-kaya (mainly North American spruce) and other woods. Check the wood and the construction separately.
On a tight budget, what should I give up first? The realistic sequence is: drop the “one piece” requirement first, secure the thickness, then consider the wood. For a board you will play on, that sequence costs you the least satisfaction.
Related pages
- How to Choose a Go Board: Wood, Form and Thickness
- Honkaya vs Shinkaya
- Go & Shogi Board Thickness
- Where to Buy Go Equipment Outside Japan
This page sets out the general difference between one-piece and joined go boards, with reference to Maekawa Kaya Goban-ten (https://www.maekawa-kayagoban.co.jp/hpgen/HPB/entries/10.html , checked 6 October 2026). For the construction, wood and condition of a particular board, see it in person at a specialist. Kayajudo is an independent guide to Japanese go and shogi equipment, and we can also order boards, stones and pieces from makers and shops in Japan for you and ship them abroad — see Ordering from overseas.