Manufacturer · Fashion & Home Accessories
The best choice for a decorative pillowcase is an invisible zip for pillowcases, placed in the bottom seam, about 5–10 cm shorter than the pillowcase side – for example, 35–40 cm for a 45 × 45 cm pillow. The zip is sewn in before the other seams, matching the fabric colour, so the pillowcase looks like it has no opening. For seats and upholstery with heavier use, a stronger spiral zip is often preferred.
Why choose an invisible zip for pillowcases
Decorative pillows are visible from all sides. A visible zip with a flap or exposed teeth disrupts the pattern and makes the pillowcase look “technical.” The invisible zip solves this: only the small pull tab is visible, and the seam looks like any other. Additionally, the invisible zip is thin and soft, so it doesn’t hurt when leaning on it or scratch furniture.
A zippered pillowcase is easy to remove for washing, and the filling can be replaced – which is why zips are preferred over hand sewing or envelope overlaps for tighter designs.
Where to place the invisible zip
In the bottom seam
The most common option. The zip is sewn into the seam between the front and back parts, on the side usually at the bottom. The pillowcase looks the same front and back.
On the back of the pillowcase
The zip is placed in a seam in the middle of the back panel. This is convenient when the front and back are made of different fabrics or when the front has embroidery, appliqué, or fringes on the edges.
For pillowcases with piping
If the pillowcase has piping along the edges, the zip is sewn between the piping and the back panel. A zipper foot for invisible zips is used first, then a regular zipper foot that sews close to the piping.
Recommended invisible zip length for pillowcases
| Pillowcase Size | Approximate Zip Length |
|---|---|
| 30 × 30 cm | 20–25 cm |
| 40 × 40 cm | 30–35 cm |
| 45 × 45 cm | 35–40 cm |
| 50 × 50 cm | 40–45 cm |
| 60 × 60 cm | 50–55 cm |
| 30 × 50 cm (long side) | 40–45 cm |
The rule is to leave a few centimetres of seam allowance on both sides at the corners. This keeps the corners strong and well-shaped, and the opening wide enough to insert the filling. If the filling is dense or fluffy, choose the longer zip length for easier insertion and removal.
How to sew an invisible zip into a pillowcase
- Finish the edges of the zip side on both fabric parts with overlock or zigzag stitch.
- Press the zip coil flat with a cool iron.
- Centre the zip along the side and mark its start and end points.
- Sew the first side of the zip with an invisible zipper foot to the front fabric, right sides together.
- Sew the second side to the back fabric the same way.
- Close the zip and sew the seam from both zip ends to the corners with a regular zipper foot.
- Open the zip halfway – this is important to be able to turn the pillowcase inside out later.
- Sew the remaining three sides, trim the corners, and turn the pillowcase right side out.
If you forget to open the zip before sewing the last sides, you will have to rip the seam – a common mistake even among experienced sewers.
Invisible zip for seats and upholstery
For seats, garden furniture cushions, sofas, and removable upholstery, the load on the zip is higher – people sit on it, and the filling is dense. There are two options here:
- Invisible zip – for decorative seats and light covers where appearance is key.
- Spiral zip with a larger size – for mattresses, foam seats, and covers that are removed often. This zip is stronger and often used as spiral zip by the metre with separate sliders, allowing long openings including corners.
For upholstery, the zip is usually placed on the back or bottom where it is not visible, so reliability is more important than invisibility.
Colour and fabric considerations
- Choose a zip colour matching the fabric background or the back panel if it is plain.
- For velvet and heavy upholstery fabrics, use longer stitches and reduce presser foot pressure.
- For linen and cotton, stabilising the seam allowances is optional but helps achieve a straight seam.
- For garden cushions, select zips and threads that withstand washing and moisture.
Invisible zip or envelope overlap
An alternative to a zip is a back made of two overlapping panels. This is quicker to sew, but the pillowcase fits more loosely, and with dense filling the overlap may open. The invisible zip provides a tight, “hotel-style” look and is preferred for higher-end collections.
Washing pillowcases with invisible zips
Close the zip before washing – an open invisible zip can catch and deform. Turn the pillowcase inside out and wash according to the fabric care label. Iron the zip from the wrong side at low temperature, as the nylon coil does not tolerate high heat.
For home textile manufacturers
When sewing pillowcases in series, standardise zip lengths by pillowcase size and order zip colours matching fabric swatches. This speeds up cutting and sewing and reduces stock leftovers. If producing collections in several colours, coordinate zip palettes in advance to avoid waiting for separate deliveries for each shade.
Invisible zips for home textiles by Polkom
Polkom manufactures and delivers invisible zips for pillowcases, cushions, and upholstery in various lengths and a wide colour range, as well as spiral zips by the metre for heavier-use items. Send a request with your pillowcase sizes, colours, and quantities – we will prepare an offer and samples.
