Ring with center band
This two-toned ring was created in Blender and printed with ebony wood filament for the outer edges and bamboo for the center band. Ulitimaker Cura was used to slice and the "Pause at height" option was added to change filament during the print. Infill is at 100% because the ring is so thin and no supports were needed. The default size for the STL is Men's 9~ish, but can be scaled to suit your needs.