From https://senseis.xmp.net/?EquipmentDimensions
Dimension SI Imperial Japanese (mm) (inch) Board width 424.2 16 23/32 1.4 shaku 尺 Board length 454.5 17 29/32 1.5 shaku 尺 Board thickness 151.5 5 31/32 0.5 shaku 尺 Line spacing width-wise 22 7/8 7.26 bu 分 Line spacing length-wise 23.7 15/16 7.82 bu 分 Line thickness 1 1/32 0.3 bu 分 Star point marker diameter 4 5/32 1.2 bu 分 Stone diameter 22.5 29/32 7.5 bu 分
(424.2mm wide - (18 stripes * 22mm)) / 2 sides = 14.099mm border width-wise (454.5mm long - (18 stripes * 23.7mm)) / 2 sides = 13.95mm border length-wise
So we'll assume a 14mm border all around.
13 lines / 12 stripes * 22mm width-wise spacing = 264mm wide without border 264mm + (2 * 14mm) = 292mm wide = 11.496 in
13 lines / 12 stripes * 23.7mm length-wise spacing = 284.4mm long without border 284.4mm + (2 * 14mm) = 312.4mm long = 12.299 in
9 lines / 8 stripes * 22mm width-wise spacing = 176 mm wide without border 176 mm wide + (2 * 14mm) = 204mm wide overall = 8.031 inches wide
9 lines / 8 stripes * 23.7mm length-wise spacing = 189.6mm long without border 189.6mm long + (2 * 14mm) = 217.6mm long overall = 8.567 inches long
- 18ga dead soft red brass wire (50ft will cover almost one 19x19 board)
- 4mm brass rod stock for star points