Grommets and eyelets are metal hardware that can be applied to leather work to reinforce holes in the leather. For example, if you have a hole where a string or rope will pass through. Over time, the rope’s movement will begin to wear down the leather material around the hole, weaken it, and possibly lead to a tear in the material. A grommet or eyelet will cover the inside of the hole, protecting the leather from chaffing caused by the rope.
Grommets and eyelets are available in a wide variety of sizes, colors, and materials. Some common ones include brass, steel, nickel, and copper. Their application can be for both aesthetic and functional reasons.