I used the measurements here: http://en.wikipedia.org/wiki/Go_equipment#Board

Bought a pine "stair tread" at home depot for about $11. Then I cut, sanded and coated it with polyurethane. I drew in the lines with permanent marker and T-sqaure after the first coat dried and gave it another coat of poly. I used the inside of a washer to make consistent star points. Routed in some inset for a hinge to attach the two halves (though this isn't necessary, its perfectly playable to just push the two halves together). Lightly sand the top to smooth out the poly coat.

All things said and done I could have spent about the same amount on a cheap beginner set at a store or online, but I really hate that most of them in the $30 price range are done on particle board and have plastic pieces. This let me have two size boards of solid wood and these stones for under $30 total: http://www.amazon.com/gp/product/B000Y9 ... UTF8&psc=1

There are also red oak stair treads available for about $28 that I may use for my next one.

Actually the flip side of the 9x9 has one with the tengen. Having never seen a real-life 9x9 board I just didn't see the point as its pretty obvious where the center is. Easy to add though