You only notice a back cushion when it's missing or doesn't fit properly: too thin, so you feel the frame underneath; too low, so your shoulders are left hanging in mid-air; or it slides down into the seat after the third time you sit down. Yet it's the back cushion that decides whether you stay on a garden bench or lounge for a whole evening. These five factors make the difference, including the measurements we sew most often in our workshop.
Factor 1: The filling – why a back cushion isn't a seat cushion
With a seat cushion, shape stability is what counts: a block of high-quality foam carries your body weight and springs back into shape. For the back, that same block would be a mistake. You don't lean back with your full weight – you're looking for support that follows the curve of your spine and feels soft.
That's why we deliberately fill our Monaco back cushion with foam flakes rather than a foam slab. The flakes distribute evenly through the gently rounded cushion, give way in just the right spot when you lean back, and still hold their height. The result feels like a proper cushion: cosy rather than board-like. One detail we're happy to point out: a cushion filled this way will naturally never look one hundred percent identical from piece to piece. That's exactly what gives a lounge its relaxed feel, as opposed to a waiting-room bench.
To keep the filling exactly where it belongs over the long term, we use a two-layer system: a separate inner cushion holds the antibacterial PU flakes securely together, while the removable olefin outer cover protects it and can be washed. You can read which foams we use for seat cushions, and why, on our foam page.
Factor 2: Height and shape – the trapezoid makes the backrest
The most common question before ordering is: how high should a back cushion be? Our answer comes straight from the configurator, where the classic lounge corner set-up is put together most often. These measurements have emerged as the standard:
| Measurement | Standard value Monaco | Why |
|---|---|---|
| Length | 60 cm | matches the seat width of one lounge module – one back cushion per seat |
| Height | 35 cm | supports the lower and middle back without rising above the backrest |
| Depth at the bottom | 25 cm | a wide base, so the cushion stands on its own on the seat cushion |
| Depth at the top | 20 cm | a slimmer top edge for a comfortable backward tilt |
The difference between 25 cm at the bottom and 20 cm at the top is no coincidence: the cushion is cut in a slightly trapezoid shape. This automatically tilts the leaning surface back by a few degrees, giving it the character of a genuine backrest without needing a wedge underneath. A rectangular cushion, by contrast, stands upright and pushes forward at shoulder height.
The standard values are a starting point, not a rule. If you have a high backrest or prefer to sit upright, go for 40 to 45 cm in height; for a low lounge with a deep seat, 30 to 35 cm is enough. There's just one rule of thumb to keep in mind: the back cushion should stand on the seat cushion, not beside it. So the seat depth it takes up needs to be subtracted from the overall depth of the furniture. For how to take seat and back measurements together, see our guide Custom Lounge Cushions and Pads.
Factor 3: The cover – the same fabric as the seat
Many ready-made sets cut corners on the back cushion: thinner fabric, a different dye batch, no zip. After just one season, you can clearly see the difference between the seat and back cushions. With a custom-made set, that mismatch doesn't happen, because seat and back are sewn from the same length of fabric.
Outdoors, that means olefin: the fibre absorbs virtually no water, is dyed right through its core so it won't fade, and the cover can be washed at 30 degrees. If you're torn between plain colours and woven patterns, order free fabric samples in advance and hold them right up against the furniture. For everything else that matters when choosing fabric for cushions, see Best Fabric for Outdoor Cushions?.
Factor 4: Staying in place – why good back cushions don't wander
Slipping is complaint number one when it comes to loose back cushions. The cause is almost always the shape: a soft, rectangular cushion has no defined base and pushes forward every time you sit down or stand up. The trapezoid shape from Factor 2 solves most of this problem, because the wide underside sits snugly on the seat cushion and pushes the weight back against the backrest.
For anything the shape alone can't solve, we make our own custom fastening straps: selected right in the configurator, made to the length you need, and run once around the backrest, lounger or lounge frame. This keeps the cushion exactly where it belongs, even in wind, on benches without a backrest, or on pallet furniture. Just remember to order the straps along with the cushion and measure the circumference beforehand. To see how this looks on an upright pallet, take a look at our guide Pallet Furniture Cushions. And the simplest rule of all: a back cushion that's exactly as long as the seat width can't shift sideways. That's precisely why we make the length to the exact centimetre.
Factor 5: The set – seat and back belong together
Most of our customers don't order the back cushion on its own, but together with a matching seat cushion. Visually, this creates a consistent look, and ergonomically, the proportions work: an 8 cm thick seat cushion paired with a 35 cm high, softly filled back cushion is the combination chosen most often for lounge furniture and garden benches.
As a seat cushion, the Nizza seat cushion is a great match, made to any size and with cut-outs for corner posts. For loungers and daybeds, the Milano bolster cushion takes care of neck support (or the Tulum wedge cushion as backrest, see Roll Cushion or Wedge Cushion?), and loose Cairo outdoor cushions add a splash of colour to the set. For how to plan a complete lounge set, from the corner module to the footstool, see our Lounge Furniture Cushions Guide.
The 60-second measuring check before you order
- Measure the seat width: from armrest to armrest, or per seat. This becomes the length of the back cushion. For widths over 135 cm, we add a neat centre seam.
- Measure the backrest height from the seat cushion: the back cushion should end 2 to 5 cm below the top edge of the backrest so it doesn't stick up above it.
- Check the seat depth: overall depth minus the cushion's depth at the bottom (25 cm as standard) gives you the actual seating area. Below 45 cm it gets tight, so it's better to choose a 20 cm depth instead.
- Note any obstructions: posts, struts or rounded armrests that get in the way. For seat cushions we make cut-outs; for back cushions, splitting the cushion per seat usually does the trick.
All measurements can be entered in the configurator on the product page; a quick sketch by email to support@lulu-belle.de is enough if something doesn't fit the standard grid. The basic rules for custom bench cushions are summarised in our guide Custom Bench Cushion.
What does this mean for your purchase?
You don't recognise a good back cushion by its price, but by four things: a filling that's soft yet holds its height, a trapezoid shape with a wide base, a length that exactly matches the seat width, and a cover that matches the seat cushion and can be washed. Tick these boxes, and you'll get a backrest that still looks and feels like new even after three summers. For everything else about custom-made cushions, from fabric to delivery time, see our overview page Custom Outdoor Cushions.
Frequently asked questions about custom back cushions
How high should a back cushion be?
For lounge furniture and garden benches, 35 cm has proven to be the standard: it supports the lower and middle back without rising above the backrest. For high backrests or an upright sitting position, 40 to 45 cm makes sense, while 30 cm is enough for low, flat loungers.
Are there back cushions for benches without a backrest?
Yes. On a bench without a backrest, the cushion needs something to lean against – a wall, a railing, or an upright pallet, for example. The back cushion is then made as long as the bench and fixed to the frame or railing with the custom fastening straps from the configurator. The trapezoid shape means it stands securely on its own.
Can I order a custom bench cushion with a back section?
Yes, as a set made up of the Nizza seat cushion and Monaco back cushion in matching fabric. Both parts are made individually and fitted precisely to your bench. Two separate elements are more comfortable than one continuous folding cushion, because the seat and back get different fillings.
Is an outdoor back cushion weatherproof?
The olefin cover is water-repellent, UV-resistant and mould-resistant, and the flake filling dries quickly. A short shower is no problem. During prolonged rain and over winter, the cushion should be stored dry like any other outdoor cushion; you'll find the details in our guide Caring for outdoor cushions the right way.
Is a custom back cushion also suitable for an indoor sofa?
Yes. The Monaco back cushion is designed for the patio, balcony and garden, but some of our customers deliberately use it indoors too: on corner benches, window seats or in the conservatory. The reason is the fabric: olefin feels soft, is dyed right through its core, and can be washed, which is just as practical with children and pets in the house as it is outdoors. The measurements are always made to order either way.
Sarah Engleman
Product development at Lulu-Belle. Since 2020 we've been developing custom-made outdoor cushions and furniture, hand-sewn in our own workshop – over 730 customer reviews speak for themselves.
