Linen has a quiet sort of luxury about it. It creases, it softens with every wash, and it has a natural slub that makes even the plainest cushion look as though it came from a little shop in a market town rather than a high street chain. The good news is that a simple cushion cover is one of the most forgiving projects you can take on, and if you choose an envelope opening you can skip zips, buttonholes and press studs entirely.

An envelope back is exactly what it sounds like: two overlapping panels of fabric that meet at the middle and hold the pad in place. It is neat from the outside, quick to sew, and mercifully tolerant of a slightly wobbly seam or a measurement that is a centimetre out. If you can sew a straight line, you can make one of these in an afternoon.

Choose and Prepare Your Fabric

Not all linen is equal. For cushions, look for a medium-weight linen or linen-cotton blend, roughly 170 to 260 gsm. Anything much lighter will show every lump of the pad underneath and will fray alarmingly as you cut it. Anything heavier, such as an upholstery linen, can be beautiful but is fiddly to turn through corners. A crisp, close-weave linen in a natural oatmeal, warm clay or soft sage will give you the look you want without the fight.

Linen shrinks, typically by three to five per cent, so always pre-wash before you cut. Wash at 30°C on a gentle cycle, dry on the line or on a low tumble, then press with plenty of steam whilst still slightly damp. Do this once and your finished cover will stay the size you intended.

• Fabric: allow 1.2 m of 140 cm-wide linen for a 45 cm pad
• Thread: polyester or linen thread in a colour one shade darker than the fabric
• Needle: a 90/14 sharp or denim needle handles linen beautifully
• Kit: pins or clips, fabric scissors, pinking shears if you have them, an iron, a blunt chopstick

Measuring Your Pad

Measure the pad itself, not the label. Squash it flat on the table and measure across the middle from seam to seam, then repeat in the other direction. Most pads are square and honest about it, but feather pads can vary and a cheap hollowfibre pad may be a centimetre or two generous.

Now the maths, which is simpler than it looks. Add 3 cm to your pad measurement — that is your 1.5 cm seam allowance at each side. Cut the front panel as a square of that size, then cut two back panels of the same width but shallower in depth.

For a 45 cm pad:

• Front panel: 48 cm × 48 cm
• Back panels: two pieces, each 48 cm wide × 35 cm deep

That gives you an overlap of roughly 12 cm at the centre, which is plenty to keep the pad tucked in. If your pad is plumper than average, add a centimetre to the width and height of the front panel so the cushion looks full rather than strained.

Cutting and Pressing

Linen likes to shift, so cut on a single layer with the fabric flat rather than folded. If you are worried about the grain being off, snip into the selvedge and pull a single thread across the width — the gap it leaves is a perfect straight line to cut along.

Once cut, take the two back panels and hem one long edge on each. Fold 1.5 cm to the wrong side, press, fold another 1.5 cm, press again, then stitch close to the inner fold. This is the edge that will be visible in the opening, so take your time and keep the stitching straight and even. Press the whole piece flat.

Sewing the Cover Together

Lay the front panel right side up on your table. Place one back panel on top, right side down, aligning the raw edges along one side — its hemmed edge should sit across the middle of the cushion. Place the second back panel on top of that, right side down, aligning the opposite raw edges, so the two hemmed edges overlap in the centre.

Pin or clip all the way round, easing the layers flat at the corners. Sew around the entire square with a 1.5 cm seam allowance, backstitching at the start and finish and pausing at each corner with the needle down so you can pivot neatly. Then:

• Trim the seam allowance to about 1 cm, and snip diagonally across each corner, close to the stitching but not through it
• Zigzag or overlock the raw edges to stop linen fraying, or pink them with shears
• Turn the cover right side out and push the corners out gently with a chopstick
• Press the seams and the whole cover, using steam and a little patience

Filling, Finishing and Care

Fold the pad in half, slide it through the envelope opening, then unfold it inside the cover and shake it down into the corners. It should feel snug but not tight. A quick press over the finished cushion — avoiding the pad itself — will sharpen the edges and give it that shop-bought finish.

Wash linen covers at 30°C, line dry where you can, and iron whilst slightly damp. They will soften and crease more with every wash, which is precisely the point. Once you have made one, you will almost certainly make three more — try a contrast hem in a darker linen, or a slightly deeper overlap for a chunkier pad. It is the sort of small, useful project that quietly makes a room feel finished.