
It work the same way with lines when doing interior design.

The angles in which the split almost creates a pathway to your center stone, drawing attention to it. They are also usually wider bands as well, which is great durability and you don't have to worry about the shank breaking. You have more room for more sparkle than a regular shank. A split shank is cool because it allows you to more room for encrusted diamonds, or fancy metalwork. Split shanks have been seen in both antique and modern ring styles.

A split shank is when the shank of the rings splits into two and back into one usually towards the bottom. The ring shank is the metal band in a ring. A split shank setting in an engagement ring is going to be describing the band style, rather than the center stone prong style.
