A sofa can still be perfectly comfortable while its back cushions have completely lost their shape. They sag to one side, feel empty or no longer suit your interior. Making your own loose back cushions is then a smart way to take comfort, looks and firmness back into your own hands. With the right dimensions, a suitable filling and a hard-wearing upholstery fabric, you can make cushions that look neat and stand up to daily use.
First decide: what should the back cushion do?
Don't just look at the external dimensions of the old cushion. A back cushion supports your lower back and helps determine how deep you sit on the sofa. A cushion that is too thick pushes you forward, while one that is too thin or too soft offers little support. So measure the existing cushion while it still has its shape, or determine the size you want from the backrest and seat depth of the sofa.
For a sleek, modern sofa, a rectangular cushion of limited thickness works well. If you want a relaxed, comfortable lounge look, the cushion can be fuller and softer. Also think about the number of cushions. Two wide back cushions give a calm look, while several smaller cushions are easier to move and plump up.
Choose a filling that suits the use
The filling determines whether a back cushion stays resilient. For loose back cushions, an inner cushion filled with siliconised fibre balls (also known as ball fibre) is a popular choice. This filling feels soft, distributes well and is easy to shake up again. For a slightly firmer result, you can combine fibre with foam chips.
If you want a tight, shape-retaining backrest, you can work with cold foam or polyether foam finished with Dacron. Dacron is a soft polyester wadding layer that softens sharp foam edges, fills the cushion out more nicely and prevents the fabric from rubbing directly against the foam. Foam provides more support but feels less relaxed and squashy than a fibre filling.
A good middle ground is a foam core with a generous layer of Dacron. This requires a little more precision when cutting and sewing, but gives a back cushion that keeps its shape neatly for a long time. For a sofa that is used intensively, that is often the most practical choice.
Making your own loose back cushions: gathering materials
For this project you need upholstery fabric, an inner fabric or ticking, filling, a suitable zip and strong sewing thread. For the outer cover, preferably use a genuine upholstery fabric. It is made to withstand friction, daily use and stress on the seams. Thin decorative fabric may look nice, but on a sofa it often wears through faster.
Don't choose the fabric on colour alone. A coarse-woven fabric, chenille, corduroy or bouclé gives a warm look, but each has a different effect on the shape. A sturdy woven upholstery fabric generally keeps a tight cushion in shape better. Velvet looks luxurious and feels soft, but requires attention when cutting because the pile must run in the same direction on all panels. Faux leather is easy to wipe clean, but needs a suitable needle and a slightly longer stitch to avoid unnecessary perforation.
Also have sharp fabric scissors, a tape measure, tailor's chalk, pins or fabric clips and a sewing machine ready. With thick upholstery fabric, a universal needle does not always work well. It is better to use a sturdy jeans or upholstery needle and test on an offcut first. That way you can see immediately whether the stitch stays neat and the feed dogs carry the layers properly.
1. Measure length, height and thickness carefully
Always measure in three places: length, height and thickness. If the old cushion has sagged, don't simply copy its current thickness. Compare it with the available space on the sofa and decide how far you want the cushion to protrude.
Add 1 to 1.5 centimetres of seam allowance to each pattern piece. So for a cushion of 60 x 45 x 15 centimetres you don't need a front panel of exactly 60 x 45 centimetres, but a panel including seam allowance. Write down all dimensions straight away and note which size is the finished size. That avoids confusion when cutting.
2. Make a simple pattern for a box cushion
The most common shape is a box cushion: a front panel, a back panel and a long strip for the sides. This side strip is also called the boxing. The width of the boxing is the desired thickness of the cushion, plus seam allowance on both sides.
You calculate the length of the boxing from the circumference of the front panel. For a rectangular cushion that is twice the length plus twice the height. Preferably cut the boxing in one piece, if your fabric width allows it: fewer seams look better and are stronger. If you do have to join it, place the seam on a less conspicuous side rather than exactly on a corner.
3. Cut the fabric paying attention to direction and pattern
Lay the fabric flat and cut all pieces on the same grain. With a plain fabric this seems less important, but the fabric can still drape or reflect differently if pieces are turned. With corduroy, velvet and printed fabrics, a fixed direction is essential.
Also watch out for pattern repeats in the fabric. Stripes, checks and distinct weave patterns must run through on the front and back panels. Take your time over this. A few centimetres of extra fabric waste is often better than a cushion on which the stripes end crookedly.
4. Sew a separate inner cover first
An inner cover keeps fibre filling in place and protects the outer cover from the inside. Use a sturdy, densely woven inner fabric for this. Sew this cover using the same pattern as the outer cover, but leave an opening of about 20 to 30 centimetres in one seam.
Fill the inner cover little by little. Always spread the fibres right into the corners before adding more. A common mistake is stuffing the cover too quickly. The middle then becomes hard, the corners stay empty and lumps form. Fill a little less than you think and test the cushion against the backrest. You can always add more.
Close the filling opening securely by hand with a ladder stitch or sew it shut on the machine. With a foam-core cushion, the inner cover can fit snugly. First wrap the core in Dacron and, if necessary, fix it with a suitable spray adhesive so the wadding layer does not shift when you insert it.
5. Insert the zip in the outer cover
A removable cover is worth the effort. You can wash it according to the fabric's instructions, have it cleaned or replace it in time without making a whole new cushion. Preferably place the zip in the bottom or back of the cushion so it is barely visible when you are sitting.
Sew the zip into a section of the boxing first. Work calmly and check that the zip opens smoothly before you close the rest of the cover. Choose a zip that covers almost the full length of the side. An opening that is too short makes it difficult to get a filled inner cushion neatly into the cover.
6. Sew the boxing and panels together
First pin or clip the boxing to the front panel. Start on a straight side, not on a corner, and distribute the fabric evenly. Very carefully snip into the seam allowance at the corners, to just before the stitching. This lets the fabric turn neatly without the corner pulling.
Then sew the back panel to the other side of the boxing. For most upholstery fabrics, use a stitch length of about 3 to 3.5 millimetres. A stitch that is too small can weaken the fabric through too many perforations, especially with faux leather. If necessary, finish seams that are under a lot of tension with a second line of stitching just next to the first seam.
7. Turn, fill and assess the result
Turn the cover through the open zip and carefully push out the corners with a blunt tool. Don't use sharp scissor points, as you can easily poke through the fabric. Then put the inner cushion into the cover and spread the filling again with your hands.
Only assess the back cushion once it is on the sofa. Check whether the height is even, whether the seams run straight and whether you sit comfortably. Does the cushion feel too loose? Then add filling. Is it too hard or too plump, take out a small amount. This ability to adjust is exactly what makes making your own so practical.
Details that make the difference
A piping along the edges gives a loose back cushion a professional, finished look. With plain fabric in particular, a contrasting piping can work well. If you choose piping in the same colour, the effect is more subtle but the shape remains more pronounced. Bear in mind that sewing piping requires more precision, especially at the corners.
Buttons, buttoning or decorative stitching are also possible, but use them deliberately. A deeply buttoned back cushion looks classic, but is more labour-intensive and less easy to wash. For a first project, a crisp box cushion with a zip is usually the best start. At BLADI upholstery fabrics you will find a wide choice of upholstery fabrics, Dacron, filling, zips and other upholstery supplies for this.
Make one test cushion first before cutting all the covers. This lets you check not only the size, but also how the fabric behaves, how much filling feels comfortable and whether the zip opening you chose is wide enough. If that first cushion feels right, the rest of the sofa becomes much easier – and you get exactly the comfort that suits your interior.
