|A Hanging Snap is a very handy technique to deploy when you wish to keep two edges abutted rather than overlapped. I recently used 2 of them to close a close-fitting standing collar on a knit top. With them, I was able to replace a zipper with 2 snaps and a slit/keyhole opening below the collar. I like my method much better than a zipper in some situations, and especially on a knit fabric.
Here's how to do it. Note: Both sides of the snap will be sewn on the inside of the garment instead of the usual one inside and one outside.
Sew the female half of the snap right at the edge of one side of your opening. You want to get as close as you can to the edge without having the snap show from the outside.
Sew the male half of the snap by one hole only to the other side of the opening, lining it up with the first half. It's possible to snap the two halves and still be able to take a stitch into the hole of the male half only, allowing you to achieve perfect placement. Then unsnap and finish stitching. Stitch securely since you're only going to have one point of attachment on this half.
Right Side, with Snaps Closed
Wrong Side, with Snaps Closed