Invisible Zips for Dresses – Length, Colour and Placement

Invisible zips for dresses are chosen with a fine nylon coil (most often No. 3) and a length usually between 40 and 60 cm for a back seam and about 20–30 cm for a side seam. The tape colour should match the fabric as closely as possible, and the zip should be a few centimetres longer than the opening. This way the dress is easy to put on, and only the small pull of the zip is visible.

Why invisible zips are the standard for dresses

A dress is a garment where the line of the silhouette matters most. A visible zip with exposed teeth interrupts this line, so formal, evening, cocktail and everyday dresses almost always use an invisible zip. It is sewn into the seam so that from the outside the seam looks continuous. Invisible zips for dresses are light, flexible and do not create a stiff edge along the back or at the waist.

Where the zip goes on a dress

Centre back seam

The most common option. The zip starts at the neckline or the top edge of the back and runs down to the waist or below. It allows a wide opening and easy dressing, especially with fitted styles.

Side seam

It is used when the back must stay clean – on styles with a deep back neckline, draping or decorative elements. The zip is under the arm and runs down to the hip. The opening is shorter, so the dress must have enough ease or stretch.

Zips in sleeves and details

Short invisible zips are used in narrow sleeves, at the bottom of very fitted dress skirts and in corsets, where a cut without a zip would make dressing difficult.

How long a zip for a dress

Measure the opening on the finished dress – from the top seam (neckline or facing) to the point where the body passes through freely. Add 2–3 cm, because the foot cannot sew right up to the slider and the excess stays below the seam. For a size range the length is calculated for each size or at least for groups of sizes.

Colour of the invisible zip for a dress

Even though it is "invisible", the edge of the tape and the pull can show during movement. That is why the colour matters:

• Tone on tone with the fabric – the basic rule. It is matched to a physical sample in daylight.
• With patterned fabrics – choose the colour of the background or the darkest predominant shade.
• With sheer fabrics – the tape can show through; choose the tone closest to the fabric or the lining, depending on which is visible.
• Pull – as standard it is in the colour of the tape, but for evening dresses metal, pearl or decorative pulls are also used.

Invisible zip for a bridal or evening gown

On bridal and evening gowns the zip carries considerable load – the bodice is fitted, the fabric is heavy and there is often embroidery, lace or sequins. Therefore:

• choose a quality invisible zip with a smooth action and a strong tape;
• reinforce the zip area with stay tape and, if needed, an additional inner tape;
• consider combining the invisible zip with an inner hook fastening at the top end to take the strain;
• on elaborate styles the zip is often covered with a decorative row of buttons with loops – the zip is the functional closure and the buttons the decoration.

For inner fastenings, wire hooks and eyes are suitable, as they take the load above the zip.

Fabrics and their particularities

• Silk, chiffon, georgette – very thin; use a fine needle and stay tape, sew slowly.
• Satin and taffeta – pucker easily; reduce the presser foot pressure.
• Jersey and stretch knits – stretch; stabilise the seam allowances without fail.
• Lace – the zip is sewn to the underlying fabric and the lace is appliquéd on top by hand.
• Velvet – the pile slips; secure with more pins or a hand tacking stitch.

Common mistakes with a dress zip

1. The zip is exactly the length of the opening and the dress is hard to put on.
2. The tape is a different tone and shows during movement.
3. The seam below the zip forms a bubble because it was not started exactly at the last stitch.
4. The horizontal seams and the waist do not line up on both sides of the zip.
5. The lining is sewn too close to the coil and the slider catches it.

How to order invisible zips for a dress collection

When you sew a series of dresses in several colours and sizes, prepare a zip specification before ordering. It saves mistakes and lets the supplier select exact shades:

• lengths by size or size groups;
• colours with a physical sample of each fabric or a Pantone reference;
• type of pull – standard in the colour of the tape, metal or decorative;
• coil size, if the fabric is very fine or heavier;
• approximate quantity per colour and length.

With such a specification, samples are usually approved the first time.

Invisible zips for dresses from Polkom

Polkom supplies wholesale invisible zips for dresses in various lengths and a large palette of colours, matching the shade to a fabric sample. We also offer original YKK invisible zips for more demanding styles. Send an inquiry with the lengths and colours for your collection – we will prepare samples.