Silvan wrote...

http://www.houseofstaunton.com/faq.html#001

Interesting reference; thanks.

1. How do you choose the right size squares to match your set to a board?
The proper square size for a set of properly proportioned Staunton chessmen
is such that the width of the base of the King should be 78% of the width
of a square. So, divide the King's base diameter by 0.78 and you get the
proper square size. You can increase the square size by 1/8", but the
square size should not be any smaller. For example, a Staunton King with a
base diameter of 1.75" would require a square size of 1.75"/0.78 = 2.25".
Hence, you should use a chessboard with either 2-1/4" or 2-3/8" (+1/8").

This size relationship between the pieces and the boards results in a
crowded board, in my opinion. It is certainly not the worst I have seen
(I think those Mexican agate sets would win that prize), but it is
quite a bit more crowded than standard competition sets and boards. These
typically have a King base diameter between 69% and 74% of the square
width.

I would also note that the fixed 1/8" buffer is probably an ok variance
for regular sized boards, but that it makes better sense to use a larger
variance for larger sets. I don't imagine a 1/8" larger square size would
be noticeable at all in a lawn or park set.

Cheers!

Jim