A zipper is a fastening device with interlocking teeth. Two strips of teeth are joined or separated by a sliding tab. The teeth are mounted on tape, which is sewn into the garment. When the slider moves, it forces the teeth together or apart. The design is simple and effective. Zippers appear on jackets, trousers, dresses, bags, and boots.

The modern zipper was developed in the late 19th century. Elias Howe patented an early version in 1851, but it did not work well. Whitcomb Judson patented a clasp locker in 1893 and displayed it at the Chicago World's Fair. Gideon Sundback improved the design in 1913 and created the modern metal zipper. The name came from the B.F. Goodrich Company, which used zippers on rubber boots and liked the sound the slider made. Early zippers were used on boots and tobacco pouches. They moved to clothing in the 1930s, when fashion designers adopted them for children's clothing and men's trousers.

Types vary. Metal zippers are strong and visible. Plastic zippers are lightweight and colorful. Coil zippers are flexible and common on bags and sportswear. Invisible zippers hide in seams for a clean look. Two-way zippers open from both ends. Water-resistant zippers use coated teeth and are used on outdoor gear. Quality matters. A cheap zipper jams or breaks. A good one slides smoothly for years. Lubricating with wax or graphite can extend its life. When a zipper fails, replacing it requires unpicking the seam and sewing in a new one.

Common types

• Metal
• Plastic
• Coil
• Invisible
• Two-way and water-resistant