On the hunt for my first full size go set on a budget, I picked up some second hand stones online… As far as I can tell, they’re single convex Yunzi (the black stones have a green translucence when held up to the light), but measure 24mm in diameter! Is this a size that is used? Are there standard boards that would accommodate this size? I didn’t find much online, so thought I’d see what everyone here thinks 
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Your post made me curious. I knew that Yunzi stones are a little bigger (in width) compared to standard / Japanese stones and do not fit a japanese board very well but it appears that there are different sizes!
(From Yellow Mountain website)
(From wikipedia website)
Your set is definitely not going to fit any standard size board. Finding a suitable one might prove quite a challenge. The fastest and cheapest option is make one yourself. There is a thread on that topic which can help you out.
Good luck!
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Thanks for the link! I tried drawing out a few squares of a standard-ish grid on paper and perhaps unsurprisingly it doesn’t take long for the extra mm to add up.
I read somewhere that some stones are a fraction oversize to dissuade perfectly straight lines from forming. I think in part due to the single convex shape, my stones didn’t nudge each other into any sensible formation. I think the overlap must be in the z-plane for such stones, which I can picture for bi-convex.
Well, maybe the only solution is to build a custom board… I don’t really have much access to a workshop, and very little woodworking experience so novice-friendly solutions will be the way to go. I do own a few hand tools so there’s something. If I get started (or if anyone has advice for doing this without a workshop!) I’ll hop over to the thread linked above on building go and 
I wonder where these stones came from… Is anyone out there using such giants 
Buying a Chinese Go board would probably work. Yellow Mountain Imports used to sell a variety of boards, many of Chinese origin, but it seems that right now, they only list one Go board on their website, and it is specifically noted as Japanese dimensions.
I have an inexpensive board (which I believe was made in China) where the “squares” are 23mm by 25mm. I found that many years ago in a local game shop.
I just did a quick search and found this option on Amazon, which looks very similar to the larger Go board that I own, and it indicates that it was made in China: Amazon.com: Go Board : Toys & Games
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