Q: Which zipper suits a fitted dress?
A fitted dress normally uses a size 3 invisible nylon coil, closed-end, with an invisible slider and a hook and eye at the top. The invisible construction hides the chain inside the seam fold, which is what a close-fitting bodice needs; on heavy satin or a beaded panel, move up to a size 4.5 so the chain can take the strain without spreading. Set the zip 2 to 3 mm from the fold and grade the seam allowance so the tape does not show through.
- Size 3 invisible coil; size 4.5 for heavy or beaded fabric.
- Invisible slider plus a hook and eye at the neckline.
- Stabilize the waist seam before inserting the zip.
Waviness is the common failure, and it almost always comes from stretching the tape while sewing or from an unsupported waist seam. Press the seam, fuse a strip of interfacing and let the fabric relax before the final stitch. The second pitfall is heat: a plastic coil melts under a hot iron, so press through a cloth and never directly on the teeth. The hook and eye, not the slider, should carry the top of the opening.