Zipper types: coil, metal, invisible and separating

Zipper types

Construction decides behaviour. If you remember nothing else: closed-end coil stays joined at the bottom; separating opens like a jacket; invisible hides; metal shows on purpose.

• Nylon coil (closed-end)

  Built: A continuous nylon or polyester coil sewn to tape, with a bottom stop so the slider cannot run off. The most common dress and skirt zip.

  Use it for: Skirt side seams, dress backs, pouches, cushion covers, anywhere the zip stays attached at the bottom. Lightweight, inexpensive, and it survives a wash.

  Skip it for: Jackets that must open all the way, or heavy bags that will grind the coil. Coil teeth can split if a thread jams them; they also melt under a careless iron.

• Invisible (concealed)

  Built: Coil teeth that roll to the back of the tape so only a thin seam shows on the face. Needs an invisible zipper foot.

  Use it for: Dress backs, fitted side seams, anywhere you want a closure that reads as a seam. The default for a clean garment finish.

  Skip it for: Thick coatings, pile, or seams you will topstitch heavily: the teeth need to seat into the foot groove. Also a poor choice if you do not have the foot; a regular zipper foot will not bury the coil.

• Metal

  Built: Individual brass, aluminium or nickel teeth clamped onto tape. Heavier, louder, and they take heat better than coil.

  Use it for: Jeans, workwear, leather and vinyl bags, anything that should look like hardware. Metal is the right visual for denim even when a strong coil would function.

  Skip it for: Fine silks and baby clothes: the teeth print through and the weight drags. Aluminium teeth bend; brass is the more durable metal.

• Separating (open-end)

  Built: The slider comes off one side at the bottom so the two tapes part completely. Jacket and cardigan zips.

  Use it for: Jackets, hoodies, coats, vest fronts: any opening that has to divide like a button band. Buy the length of the finished opening; you cannot easily shorten a separating zip from the bottom.

  Skip it for: Skirts, dresses and bags that should stay joined at one end. A separating zip on a pouch is a zip that dumps the contents.

• Two-way separating

  Built: Two sliders on a separating zip, so you can open from the top, the hem, or both.

  Use it for: Coats you sit in, long puffers, some bags. The extra slider is the whole point.

  Skip it for: Short openings: two sliders on a 12 cm zip just fight each other.

• Plastic moulded (Vislon-style)

  Built: Chunky individual plastic teeth, not a coil. Lighter than metal, more weather-tolerant.

  Use it for: Outdoor gear, rain jackets, tote bags, sportswear. The teeth are visible on purpose.

  Skip it for: Tailored garments where you want the zip to disappear. Also brittle in deep cold if the plastic is cheap.

Shop zippers coil, metal and invisible, in useful lengths, or the wider sewing notions shelf. Pulls and charms live with charms.

Lengths and where each sits

Zipper length is the length of the teeth, not the tape tails. Measure the finished opening on the cloth. Closed-end zips can be shortened from the top; separating zips should be bought to length.

Shortening a closed-end zip: sew a dense bar-tack or a few tight zigzag stitches across the teeth where the new bottom should sit, then cut the extra tape 2 cm below. Do not do this to a separating zip — the insertion pin is the bottom, and you cannot invent a new one.

How to sew a centred zip

A centred zip is the everyday install: teeth in a slot, two even rows of stitching. Lapped zips (one flap covering the teeth) are the trouser-fly cousin; the prep is the same: a basted seam and a zipper foot.

1. Sew below, baste the opening. Regular stitch below the zip. Baste the opening closed on the seam line so the edges meet as they will when worn.
2. Press open and place. Press the seam. Lay the zip face-down on the wrong side, teeth on the basting. Pin or use temporary basting glue from the fabric glue shelf so nothing wanders. When glue helps a zip →.
3. Stitch with a zipper foot. From the right side, stitch down one side, across just above the stop, and up the other. Keep an even distance from the teeth. Stop with the needle down to walk the slider out of the way if it blocks the foot.
4. Unpick the basting. The teeth should sit in a clean slot. Open and close once before you finish the rest of the garment: a catch now is a five-minute fix; a catch after the facing is in is not.

Invisible zips

An invisible zip is sewn before the rest of the seam, not after. Open the zip. Unroll the coil with a fingernail so it sits in the groove of the invisible zipper foot. Stitch each tape to its garment edge, close the zip, then sew the seam below the stop: as close as you can get without hitting the slider.

• Press the tapes toward the garment, not over the teeth, so the coil can roll under.
• Do not topstitch an invisible zip unless the pattern asks. Topstitching is how you turn it back into a regular zip.
• If the teeth show on the face, the coil was not unrolled into the foot, or the stitch line sat too far from the teeth.

Feet, needles and thread

• Zipper foot: the default for centred and lapped zips. Machine accessories if you need the foot.
• Invisible zipper foot: grooves that bury the coil. Not optional for a concealed zip that actually conceals.
• Universal 80/12 for most wovens; jeans needle through denim and metal zips; microtex on fine or coated cloth. Needle types and sizes →.
• Polyester thread from the sewing thread shelf. Cotton has less abrasion resistance where the slider rubs.

Closures that are not zips: buttons, types and how to sew them on → and elastic for waistbands →. A first garment that skips a zip entirely is often the kinder start — beginner sewing patterns →.

Quick answers

What is the difference between a coil zipper and a metal zipper?

Coil zippers have a continuous nylon or polyester coil: light, washable, fine for dresses and pouches. Metal zippers have individual teeth clamped to the tape: heavier, more durable on jeans and bags, and they look like hardware. Function overlaps; the visual and the weight usually decide.

When should I use an invisible zipper?

Whenever you want the closure to read as a seam: dress backs, fitted side seams, some cushion backs. You need an invisible zipper foot so the teeth roll under as you sew. If you do not have the foot, a regular lapped or centred zip with a standard zipper foot is the honest alternative.

How do I know what length zipper to buy?

Measure the finished opening on the garment or bag, not the paper pattern alone. Closed-end zips can be shortened from the top by sewing a new stop and cutting off the extra tape. Separating zips should be bought at the finished length: shortening from the bottom destroys the insertion pin.

Can I sew a zipper without a zipper foot?

You can get close with a regular foot by shifting the needle, but the foot sits on the teeth and the line wanders. A zipper foot (and an invisible foot for concealed zips) is a small, one-time buy that pays for itself on the first dress. They live with machine accessories.

Why does my zipper wave or pucker?

The tape was stretched as you sewed, the seam allowance was uneven, or the fabric grew and the zip did not. Baste the zip first: glue-baste or hand-baste: sew with the zip, not against it, and press the seam before you install. Interfacing a fine fabric’s seam allowance stops the wobble.

What needle should I use to sew a zipper?

A universal 80/12 for most wovens; a jeans needle for denim and metal zips through multiple layers; a microtex for fine or dense cloth. Stitch length 2.5 mm, slightly longer over the slider area if you sew around it. Polyester thread: it takes the abrasion at the teeth.