Replacing an Invisible Zip in a Dress

What makes a zip 'invisible'?

An invisible zip is a coil zipper mounted in reverse: the teeth are rolled towards the wrong side, so they sit hidden behind the fabric when the zip is closed. From the outside you see only a seam and a small pull – no row of teeth and no stitching. It is sewn in with a special invisible zipper foot that unrolls the coil so the needle stitches right up against the teeth, and it is exactly this precision that makes the seam disappear. An ordinary zip, by contrast, has visible teeth and a line of stitching along the tape. Invisible zips usually sit at the centre back or in the left side seam of dresses, skirts and formalwear, often with a lining hand-sewn around the zip.

Common invisible-zip failures

Invisible zips fail in a few typical ways. Recognise yours before you choose a fix:

• The slider has come off: invisible zips shed their slider more easily than others, because it runs on a thin coil. If the coil is intact, the slider can often be refitted or replaced.
• The coil is crushed or melted: if you have ironed straight over the zip, the plastic may have melted or flattened. The slider then no longer grips, and the zip must be replaced.
• The zip glides open: a worn slider no longer squeezes the teeth together, even though the coil looks intact.
• Teeth pulled apart: yank an invisible zip hard and the coil can lift off the tape in one section – that cannot be sewn back invisibly, and the zip must be replaced.

Try to rescue the slider first

If only the slider has come loose and the coil is otherwise intact, you can try this before giving up on the whole zip:

1. Check that the coil is whole and even all the way – if it is melted, crushed or missing, rescuing the slider won't help.
2. If the slider has come off the top, gently feed it back on from the top end, narrow opening first, with one row of coil into each channel.
3. Stop the slider running off again by sewing a small thread stop (a few tight stitches across) at the top of the tape where the original stop sat.
4. Do not iron directly on the coil of an invisible zip – it is plastic and melts. Always use a cloth in between and keep the iron off the teeth themselves.
5. If the coil is damaged, or the seams on each side no longer meet, it is a replacement – not an adjustment.

Why replacing it in a dress is precision work

Replacing an invisible zip looks simple, but in a dress the margins are small:

• The seam and lining have to be unpicked carefully, and the lining is usually hand-sewn back around the zip afterwards.
• The new zip must be an invisible type in exactly the same length and colour – the colour shows clearly against a plain dress fabric, so it has to match.
• If a waist seam or a pattern runs across the zip, it must meet identically on both sides, or the line jumps to the eye.
• Delicate, slippery fabrics like silk, chiffon and satin shift and mark easily from needle holes, so the zip must go in without tightening the seam.
• The goal is for the new zip to vanish into the seam again – which takes the same invisible-foot technique used when the dress was first made.

Send the dress to us

If you are unsure whether the slider can be rescued or the whole zip must be replaced – or you want the seam to be as invisible as before – you can send the dress to us. We assess the zip and replace what is needed, with an invisible zip in the right length and colour, set it so the seams meet, and secure the lining neatly back. If the dress also needs a hem or a fit adjustment, we handle it in the same round. We help you across all of Norway, you order online, and you see the price before you order.

Frequently asked questions