囲碁将棋盤 榧寿堂 ／ How Go Board Lines Are Made: Tachi-mori, and Why a Sword Is Involved
How Go Board Lines Are Made: Tachi-mori, and Why a Sword Is Involved
Two go boards can be the same wood, the same thickness, and the same price bracket, and still be separated by one thing a photograph rarely shows: how the lines were made. On a serious board they are not printed. They are lacquer, raised above the surface, applied with a tool most people would not guess.
Tachi-mori: lines cut with a sword
Tachi-mori (太刀盛り) uses a Japanese sword with a rounded edge. Warmed lacquer is applied to the blade, and the craftsman lays the line down with a cutting motion across the board.
There is no jig and no guide block. The blade follows pencil marks, and the hand does the rest. It is the stage of board-making with the least margin for correction — the wood underneath is already finished.
The alternatives, and what changes
| Method | Tool | Note |
|---|---|---|
| Tachi-mori (太刀盛り) | Rounded Japanese sword blade | The technique associated with top-grade boards |
| Hera-mori (へら盛り) | A spatula | Dominant in Edo-period Tokyo; still common among Tokyo makers today |
| Fude-mori (筆盛り) | A brush made of rat whiskers | The brush method |
Compared with the alternatives, tachi-mori produces three specific differences:
- The lacquer line wavers less
- The outline is clearer
- The lacquer stands higher off the surface
That third point is the one you can feel. On a printed board the grid is flat ink. On a lacquer-set board the line has height, and against a raking light it casts a shadow.
What this means when you are looking at a listing
You will rarely see “tachi-mori” written in an English listing. What you can do instead:
- Ask for a photograph taken at a low angle, not straight down. Raised lacquer shows as a ridge; printed lines do not.
- Ask whether the lines are lacquer or printed. A seller who knows the board will answer immediately; one who does not has told you something too.
- Do not treat hera-mori as a defect. It is a legitimate Tokyo tradition, not a cheap substitute. The meaningful gap is lacquer versus print, not sword versus spatula.
This sits alongside the other two things a listing tends to leave vague: what “clamshell” and “hon-kaya” actually mean, and how thickness is described.
Sources. The tachi-mori method (heated lacquer on a rounded sword blade, applied with a cutting motion, no guide block), the hera-mori spatula method and its Edo-period Tokyo association, the fude-mori rat-whisker brush, and the three stated differences — less wavering, clearer outline, higher lacquer: Japanese Wikipedia, 太刀盛り. Checked 2026-08-18. We do not stock boards, but we can order them from Japan for you (see Ordering from overseas); ask the seller directly about any specific item.