with Flat in Center
Every profile can be made with any of the inside profiles provide.
Some inside profiles suit some outside profiles better than others but all can be interchanged, you make the choice.
These images are based on a 6mm wide ring 1.8mm thick.
Total weight of the 12mm
wide ring is 8.38 grams.
These examples show how different bores can enhance the outside profiles.
this ring is the based for an eternity ring
and uses a reverse recess bore to lighten
the ring and provide a recess for the stones.
with Radiused Edges