A two-piece metal or plastic fastener consisting of a closure unit (socket) and an attaching unit (stud) that literally snap together to hold two garment components secure.
Snaps are easy and convenient both to apply and to use. Unlike buttons, snaps do not require buttonholes, which are sometimes daunting to make. Snaps are easy for children to manage and they work on a wide variety of fabric types.
Snap fasteners come in several models: the sew-on type, the post-style that is installed through a hole in the fabric and secured with a backing, and the prong style with teeth that penetrate the fabric and a ring that crimps and holds the prongs in place. The post style may require a hammer for installation. Prong-style snaps can be installed with the aid of special pliers or a punch and die set.
The components of post- and prong-style snaps are the closure unit and the attaching unit. Prong-style snaps come in long-prong industrial versions and shorter-prong versions. The long-prong snap will hold more securely.
Prong-style snaps are recommended for loosely woven fabric. You will need to interface the fabric with a non-fusible material such as cotton or muslin to strengthen the fabric. Use prong-style snaps on cardigans, shirts, vests, light jackets, children's wear, fleece garments, western wear, and home decor.
Post-style snaps work well with densely woven natural or synthetic fibers. Use post-style snaps for leather jackets, denim jackets, jeans, heavy outerwear, purses and bags.
Sew-on snaps are used to hold overlapping edges together. The parts of the sew-on snap are the stud (top) half with a small protrusion from the center, and the socket (bottom) half that receives and holds the top half. Sew-on snaps come in clear, lightweight nylon, and on snap tape for use in children's wear and on pillow and duvet covers. Stand-alone snaps are available in a range of sizes and in black, chrome, bronze, and white finishes. They are primarily used in areas not subject to high stress, such as blouse fronts, jacket fronts, and secondary interior waistband support.
Outside the U.S., they are called press studs.
Snaps were invented centuries ago. They have been discovered in the horse halters of the Chinese Terracotta Army from 210 B.C.
In more recent eras, sew-on snap fasteners were used in the 1800's on lingerie and costumes. A type of snap was patented in Germany by Heribert Bauer in 1885 for use on men's trousers. A Danish inventor had his own version. Both European versions had a spring in the top disc instead of a groove.
In the U.S. in the 1900's a designer of Western wear modified the design of prong snaps with an inset of mother-of-pearl. They are now the traditional closure for Western wear.
Tips & Tricks
Don't try to mix parts of post- or prong-style snaps from different manufacturers. Chances are that they won't fit together, as snaps are not standardized.
Test to see that snaps are set securely by attempting to slip your thumbnail between the snap and the fabric. If the snap is well-seated, you will not be able to.
Use the center hole in sew-on snaps to line up both components precisely. Sew on one part; then line up the corresponding garment pieces and run a pin through the center hole to mark the placement of the other half of the snap.
Rub the sewn-on part of the snap with chalk; then carefully position the overlap. The chalk will leave a mark indicating where to sew the other half of the snap.
Interface the fabric under the area in which the snap is to be installed. This applies to all styles of snaps.
Always test a prong- or post-style snap application before attempting to install the snap in your project. You may need to practice to get the technique just right.
Prong and post snaps are very difficult to remove once they are installed. Be sure your markings are accurate before you apply the snaps. You want to get them placed correctly on the first try.