What size board square will work with a king with a 1 1/8 inch base diameter?
Wouldn't it be just a little bigger than the diameter, like another few eighths?
A square whose side is about 1.3 times to 1.5 times the king diameter works well. So in your case, a square with sides of one and a half inches up to an inch and three quarters.
What size board square will work with a king with a 1 1/8 inch base diameter?