Application: Sew-On Snap Buttons , also sometimes called press studs or press snaps, are best used for overlapping closures: button-front shirts, jackets, children's clothes, device cases, bags, and more. Sew-On Snaps can be easily installed by sewing through the outer loops, so there is no need for a snap tool to install them. Sewing snaps are available in a variety of colors and sizes, as well as assorted packs.