Ideal bezel dimensions

Hi all,

What would be the ideal average dimensions for a 2, 3, 4, and 5 mm
bezel setting? If you were to design the perfect setting what would
the wall thickness be? Would it be around .03 mm for a 2mm stone or
is that too thin? How much would the wall thickness vary with an
increase in the stone diameter? One of my students asked and I am
wondering what the consensus would be.