Traditional Go Game Equipment
Although one could play Go with a piece of cardboard for a board and a bag of plastic tokens, Go players pride themselves on their game sets.
The traditional Go board (called a goban in Japanese) is solid wood, about 15-20 cm thick, and stands on its own attached legs. It is preferably made from the rare golden-tinged Kaya tree (Torreya nucifera), with the very best made from Kaya trees up to 700 years old.
Players sit on reed mats (tatami) on the floor to play. The stones (go-ishi) are kept in matching solid wood pots (go-ke) and are made out of clamshell (white) and slate (black) and are extremely smooth. The natural resources of Japan have been unable to keep up with the enormous demand for the native clams and slow-growing Kaya trees; both must be of sufficient age to grow to the desired size, and they are now extremely rare at the age and quality required, raising the price of such equipment tremendously.
In clubs and at tournaments, where large numbers of sets must be maintained (and usually purchased) by one organisation, the expensive traditional sets are not usually used. For these situations, table boards (of the same design as floor boards, but only about 2-5 cm thick and without legs) are used, and the stones are made of glass rather than slate and shell. Bowls will often be plastic if wooden bowls are not available. Plastic stones could be used, but are considered inferior to glass as they are generally much lighter, and most players find that not even the lower price justifies their unpleasantness. Very high quality table boards are made of Kaya, but other woods may be used to make quality table boards, such as Hiba (Thujopsis dolabrata), Katsura (Cercidiphyllum japonicum), and Agathis.
Traditionally, the board's grid is 1.5 shaku long by 1.4 shaku wide (455 mm by 424 mm) with space beyond to allow stones to be played on the edges and corners of the grid. This often surprises newcomers: it is not a perfect square, but is longer than it is wide, in the proportion 15:14. Two reasons are frequently given for this. One is that when the players sit at the board, the angle at which they view the board gives a foreshortening of the grid; the board is slightly longer between the players to compensate for this. Another suggested reason is that the Japanese aesthetic finds structures with geometric symmetry to be in bad taste.
Traditional stones are made so that black stones are slightly larger in diameter than white; this is probably to compensate for the optical illusion created by contrasting colours that would make equal-sized white stones appear larger on the board than black stones. The difference is slight, and since its effect is to make the stones appear the same size on the board, it can be surprising to discover they are not.
The bowls for the stones are of a simple shape, like a flattened sphere with a level underside. The lid is loose-fitting and is upturned before play as a tray to collect stones captured during the game. The bowls are usually made of turned wood, although small lidded baskets of woven bamboo or reeds make an attractive cheaper alternative.
There is even an art to placing a Go stone, held between the tips of the outstretched index and middle fingers and striking the board firmly to create a sharp click. Many consider the acoustic properties of the wood of the board to be quite important. The traditional goban will usually have its underside carved with a pyramid called a heso recessed into the board. Tradition holds that this is to give a better resonance to the stone's click, but the more conventional explanation is to allow the board to expand and contract without splitting the wood. A board is seen as more attractive when it is marked with slight dents from decades - or centuries - of stones striking the surface.
