In the same family as snaps and buttons, hooks and eyes are another clasp you can use for your project.  One side of this clasp is a hook and the other side either has loop or a straight edge.  This side is considered the eye.  They hook onto each other in the middle, creating the completed clasp.  They are commonly used on areas that need a clasp but won't be under a lot of stress as they are hand sewn and therefore not as strong as a heavy duty snap or even a button.  They're mostly found above zippers as zippers tend not to go to the top of the seam and thereby they're used to finish off the closure.  You will typically find them at the top of a dress or on a waistband.