In regular ring settings, metal claws, metal channels, or metal beads are used to set a gem in a ring band. All diamond ring settings are appealing, but that is even more so on a ring featuring an invisible setting. In an invisible set ring, the center stone is set in a way that the metal is not easily visible, at least when you view it from the top. In other words, the metal used to secure or set the gem is hidden beneath it.
Invisible set rings have square cut gemstones always, as that shape is required to make the setting work. Since a square cut stone is mandatory here, you are likely to find an invisible set diamond ring that features princess cut diamonds at the center.
Look at square or a princess cut invisible set diamond rings from the top, and you are likely to see the gemstones set flush with each other. It takes a skilled jewelry designer and so much time and cost to achieve the setting with less visible metal. All that work that goes into the setting contributes to the rarity of invisible set rings.