How to sew a lapped zipper on a cushion cover

Cushion covers take a real beating in Australian living rooms. Between the summer sun streaming through the windows in Brisbane, the sudden coastal humidity in Sydney, and the ever-present threat of a toddler with a plate of vegemite toast, a handmade cover needs to be both tough and easy to remove for washing. A lapped zipper is a brilliant choice for this job because it sits flat, hides the zip teeth completely behind a fold of fabric, and gives a neat, almost tailored finish that looks right at home on a sofa or a reading chair in the sunroom.

This technique is a staple for anyone making piped cushion covers, patchwork designs, or simply wanting a more polished alternative to the standard centred zip. With a regular domestic machine, a zipper foot, and a bit of patience, you can produce covers that look store-bought but cost a fraction of what you'd pay for a designer cushion at a place like West Elm or Country Road. The method also works beautifully for seat pads on dining chairs, floor cushions in a child's play area, and even small bolster pillows.

Choosing your fabric and zipper

When you're picking materials, think about how the cover will be used. A heavy-weight linen or cotton canvas from Spotlight, Australia's biggest chain of fabric and craft stores, handles daily use well, while a quilting cotton from your local independent shop is perfect if you're piecing a patterned front. If you're in Melbourne, Tessuti on Flinders Lane stocks a gorgeous range of designer deadstock that lifts a simple cushion into something special, and Sydney sewists often pop into The Remnant Warehouse in Surry Hills for offcuts at bargain prices.

For the zipper itself, you want a standard dress zip rather than a chunky upholstery one. A 30 cm or 35 cm zip is plenty for a 45 cm square cushion. Look for metal-toothed zips at Lincraft or online from specialty suppliers if you want a more vintage look. Coil zips in a matching tone are easier to sew through and won't fight you under the presser foot. Always pre-wash your fabric the way you plan to wash the finished cover, because Australian washing machines can be aggressive on shrinkage, and there's nothing worse than a cushion that won't fit its insert after the first cycle.

Preparing the cushion panels

Cut your front and back panels exactly the same size, marking the centre of the bottom edge on each piece. If your cushion has piping, attach it to the right side of the front panel first, clipping around the curves and easing it around the corners. If you're new to piping, have a look at this practical walk-through on resizing a too-long pattern, because the same logic of trimming and re-drafting applies when your cushion panels don't quite match the zip you're using.

Press a 2 cm turning on the bottom edge of both the front and back panels, then press again to enclose the raw edge. This double-fold hem will hide the zip tape when the cover is finished and gives the lapped zipper its clean look. Run a quick basting stitch along each fold to hold it in place, or use a fabric glue stick if you'd rather skip the temporary stitching. Place the two panels right sides together, aligning the side and top edges, and pin around three sides leaving the bottom edge free for the zip.

Installing the lapped zipper

Open the zipper fully and lay it face down on the wrong side of the back panel, with the teeth centred along the pressed fold. The top stop should sit about 1 cm below the top raw edge, and the bottom stop should reach the seam allowance. Pin the zip tape to the folded edge, then flip the whole thing over so you're looking at the right side of the back panel. Fold the front panel up and out of the way for now.

Switch to your zipper foot and position the needle so it sits close to the folded edge of the back panel. Sew slowly from the top down, stopping a few millimetres before the bottom stop. Backstitch, then close the zip halfway and pivot the front panel into position, right side down, so its pressed fold overlaps the back panel fold by about 1.5 cm. This overlap is what creates the lap. Pin the front fold in place, then continue sewing along the same seam line, this time catching the front panel underneath. When you reach the bottom stop, backstitch again. The result is a single continuous stitch line that holds both folds and the zip tape in one go.

If you've never tackled a lapped zipper before, it can help to mark the seam line on the right side of the back panel with a fabric marker before you start. The mark gives you something to follow when the tape disappears under the fold. Many Aussie sewists use a washable pencil from their local Spotlight haberdashery aisle, which rubs out cleanly with a damp cloth once the seam is finished. Take your time with this step, because uneven stitching on a lapped zip is the first thing the eye notices on the finished cushion.

Finishing the cover and adding the corners

With the zip installed, sew the remaining three sides of the cushion with a 1 cm seam allowance, backstitching well at either end of the zip opening for strength. Before you turn the cover right side out, clip the corners diagonally to reduce bulk, and trim the seam allowances down to about 6 mm, especially through any thick layers where the zip tape meets the side seam.

For a boxed cushion that sits plump on the sofa, cut a small triangle of fabric from each corner before sewing the side seams. A 2.5 cm square works for a soft, casual look, while a 4 cm square gives a sharper, more architectural corner. Sew across each cut-out corner with a straight stitch, then press the seams open. This trick is widely used by quilters across Queensland and NSW, and it transforms a flat cover into something that hugs a feather insert properly.

Turn the cover right side out through the zip opening and give it a good press, pushing the corners out with a blunt chopstick or the back of a knitting needle. Insert your cushion pad, zip it up, and pop it on the couch. If you fancy a coordinated project, the Love Notions Virginia dress makes a brilliant matching set of cushion covers in a complementary print, and leftover fabric from the dress sews up beautifully into a coordinating throw pillow.

Caring for your finished cover and adapting the method

A well-made lapped zipper should glide smoothly for years if you treat it kindly. Avoid yanking the cover off by the zip pull when you're changing it, and keep metal zips away from chlorine-based bleach, which can pit the teeth over time. Most cotton and linen covers from Australian fabric shops can go through a cool machine wash inside out, then line-dried on the Hills hoist out the back.

If you'd like to vary the technique, try a contrast zip tape in a bright colour for a fun, modern look, or swap the lapped method for an exposed zip if you're after something more contemporary. You can also use the same approach on longer cushion backs for a three-seater sofa, just by extending your panels and using a 40 cm or 45 cm zip from Spotlight or your local haberdashery. If you'd like a yarn about pattern adjustments or to share your finished project, drop a line via the email list and join the growing community of Aussie indie sewists. No worries if you're a beginner, the community is wonderfully welcoming and full of folks happy to share tips over a cuppa on a Sunday arvo.

Zipper style	Best for cushion covers	Skill level	Look on the finished cover
Lapped zipper	Heavier fabrics, piped covers, anything where you want the zip hidden	Beginner to intermediate	Clean, traditional, tailored
Invisible zipper	Lightweight or drapey fabrics where you want no visible stitching	Intermediate	Sleek, minimalist, almost no zip showing
Exposed zip	Modern, casual cushions, kids' rooms, playroom floor cushions	Beginner	Bold, contemporary, zip is a design feature
Centred zip	Basic pillowcases, simple cushion backs	Beginner	Visible topstitching on both sides, utilitarian
Hand-picked zip	Heirloom or vintage-style cushions, delicate fabrics	Advanced	Almost invisible, soft, couture finish