Popular earring back designs include push backs, screw posts, latch backs, saddlebacks, lever backs and French clips. Push backs, also known as post or butterfly backs, are the standard design used on most stud-style earrings. A thin, straight wire is pushed into a small hole at the center of a butterfly-shaped back piece.
A screw post, or screw back, is similar to a push back in shape, but it has a winding groove along the post, allowing the back piece to screw on and off. Screw posts are often used on expensive studs, such as diamonds, to prevent the earring from slipping out and getting lost.
Latch-back, saddleback and lever-back styles are typically used on heavy hoop or dangle earrings. They contain a hinged post that snaps into a metal catch, which varies in shape depending on the style. Latch-back and saddleback earrings often have a loop- or U-shaped catch, while lever-back styles usually rely on a spring and lever to keep the earring closed.
French clips, or omega backs, have a clasp that snugly grips the earlobe. French backs can be designed for pierced or unpierced ears, and some styles feature a screw that can be tightened for a custom fit. This backing style is common in earrings with gemstones.