Peter, I think the only thing that can be copyrighted about this ring
is using the Cartier logo on it. I’ve made this ring from jump rings
(called a mobius weave). Perhaps calling it a Trinity Ring would be a
copyright infringement as well, but not making it. It’s just 3 pieces
of metal, soldered or fused together to form the mobius weave which
has been around for centuries. Ask any chainmailler. I see these
rings, handmade, all over the place but they’re not exactly like
Cartier’s. The treatment or design of the outer bands would make this
an original design, whether polished, stamped, or fiddled about in
any other way. The weave, is the weave, is the weave.
David, I think what you need to know is how to determine the
diameter. For that, you’d have to take into account the thickness of
the rings you’re using. So a size 8, using 3 bands at 1mm thickness,
should be at least 2mm thicker than a size 8 to account for the
offset of the added thicknesses. You’ll also need to take into
account the width of the bands. Wider bands, as you know, should be
If you want to be absolutely sure, create your three rings as “jump
rings” without soldering them closed first, and have a “fitting” with
the customer. Works for Bridal gowns, why not custom rings.
Have fun. And be original in your final product.