Manufacturer · Fashion & Home Accessories
Yes, the invisible separating zip does exist. It combines the concealed coil of an invisible zip with a box-and-pin mechanism at the bottom, allowing the zip to fully separate into two halves. It is used for fitted jackets, blazers, cardigans, dresses, and sets with front zips where the fastening must remain invisible. It is less common than the non-separating invisible zip, so lengths and colours are usually confirmed upon inquiry.
What is an invisible separating zip
The standard invisible zip is non-separating – its bottom end is closed because it is sewn into a seam that continues beneath it (on dresses, skirts or trousers). However, when the garment must open fully at the front, a separating zip is required. The invisible separating zip features:
- a reversed coil that, after sewing, is hidden in the seam just like a regular invisible zip;
- a bottom mechanism with a pin on one tape and a box on the other;
- a slim teardrop or decorative pull, which is the only visible part of the zip.
The garment front looks like a continuous seam with no visible teeth or flap.
Where the separating invisible zip is used
- Fitted jackets and blazers – minimalist front designs without buttons or visible zips.
- Knit cardigans and pullovers – the fastening does not disrupt the knit pattern.
- Dresses and jumpsuits with front zips – when the garment opens fully.
- Waistcoats and corsets – close-fitting models where the zip must lie flat.
- Children’s clothing and sleeping bags – where a smooth surface without exposed teeth is an advantage.
- Covers and upholstery – removable covers that detach completely.
Separating invisible zip or covered separating zip
When people search for “invisible separating zip,” they often mean another solution – a regular separating zip hidden under a flap or cover. Both options achieve a similar effect but in different ways:
| Criterion | Invisible Separating Zip | Covered Separating Zip |
|---|---|---|
| External appearance | Only a slim seam and pull visible | Flap or cover over the front |
| Wind protection | Weaker | Better, the flap covers the zip |
| Suitable for | Lightweight and fitted garments, knits | Outerwear, jackets, coats |
| Load capacity | Light to medium | Medium to heavy |
| Chain type | Fine nylon coil | Metal, coil or moulded |
For winter jackets and parkas that require strong load capacity and wind protection, a regular separating zip – coil or moulded – hidden under a flap is more suitable. The invisible separating zip is a solution for light and elegant garments.
How to sew an invisible separating zip
The principle is the same as for a non-separating invisible zip – using an invisible zipper foot and opened coil – but there are some differences:
- Separate the zip and sew each half separately to the corresponding garment front.
- Position the box exactly at the hem level, leaving room for its finishing. The box must not protrude below the hem.
- Mark control points – waist, pockets, neckline – on both tapes with the zip closed before sewing the second side.
- Sew to the very bottom edge – there is no continuing seam under the zip here, so both tapes are sewn fully, with the foot going around the box and pin.
- Finish the facing or lining so it does not catch in the coil.
Unlike the non-separating invisible zip, the separating one cannot be shortened from the bottom because of the mechanism. If it is too long, shorten it from the top or order the exact length.
How long should the invisible separating zip be
Measure the finished garment opening – from the hem to the upper edge of the neckline or collar. Unlike the non-separating invisible zip, no extra length is added at the bottom because the zip is sewn fully. Roughly:
- short cardigans and boleros – about 30–45 cm;
- blazers and fitted jackets – about 45–60 cm;
- dresses and jumpsuits with front zips – 60 cm or more.
Colour and pull selection
Since the front is visible with the separating invisible zip, the tape colour should match the fabric as closely as possible. The pull can be standard, metal or decorative, and for blazers and jackets, a small charm for easier grip is possible. If the garment has other details like buttons on sleeves or pockets, coordinate colours in one order.
Common mistakes with invisible separating zips
- The box is above the hem – the bottom of the front remains open and gaps when walking.
- Misaligned levels – pockets or waist on both fronts do not match due to missing control points.
- Stretched tape on knits – the front gathers and forms waves; stabilise the knit with tape.
- Wrong choice of garment – heavy outerwear with a delicate invisible zip that cannot withstand the load.
Availability and ordering
Separating invisible zips are a specialised item and are not available in all colours and lengths like standard non-separating ones. For serial production, orders are usually made to measure and colour. Minimum quantities depend on the item – send an inquiry with lengths, colours and coil size.
Invisible zips from Polkom
Polkom manufactures wholesale invisible zips – non-separating and, on request, separating – in various lengths and colours matched to fabric samples. Send an inquiry describing your model – we will advise whether an invisible separating zip or a covered separating zip is more suitable and prepare samples.
