How do I measure a triangle cushion for a custom cover?

Three numbers off the bare foam: height up the vertical back, width along the base from the front point to the rear edge, and length down the run. Height and width define the triangle; length tells us how far to extend it.

What is a triangle cushion used for outdoors?

It's the recline specialist — a backrest wedge against a wall or daybed frame, a reading support on a lounger, a leg-elevation cushion at the foot end. Anywhere flat cushions need an angle, the triangle supplies it.

What's the difference between a triangle cushion and a wedge cushion?

The front. A triangle runs its slope all the way down to a point at the base — one height describes it. A wedge is truncated: it keeps a short front wall, so it needs both a back height and a front height.

How big can a triangle cushion cover be made?

From small leg-rest wedges to full-width daybed backrests — the pattern scales with your three measurements. There's no stock-size list; steep and short or long and shallow, it's cut to your numbers.

Can triangle covers match the bench cushions beside them?

Yes — the wedge can be cut from the same Sunbrella line and color as every other cover in the collection, so the recline piece blends into the seating group instead of reading as an add-on.

Custom Waterproof Triangle Cushion Covers

Name: Triangle Cushion Cover
Brand: ZIPCovers
SKU: triangle-cushion-cover
Price: 31.5 USD
Availability: InStock

Description

A triangle cushion is a lean, not a seat. Prop it against a wall, a daybed frame, or a headboard and the sloped face turns flat lounging furniture into reading-and-recline furniture. The catch is that the angle only works if the cover preserves it — and a custom triangle cushion cover is cut from your cushion's exact three numbers, so the profile that fits your back keeps fitting it.

Three measurements describe the entire shape: the height of the vertical back, the width of the base from front to rear, and the length of the run. Those first two set your recline angle — a tall, short-based triangle sits steep for upright reading; a low, long-based one lies shallow for a gentle recline. Whatever geometry your foam carries, the cover reproduces it.

Wedges also live hard lives — dragged to the pool edge, propped on grass, leaned on for whole afternoons. A waterproof triangle cushion cover in Horizon keeps all of that on the surface, and when the original fabric gives up, a replacement triangle cushion cover renews the shaped foam for a fraction of what a new wedge costs.

The wedge usually leans against something bigger — explore every cover shape in the collection and outfit the daybed behind it too.

Why Choose Our Custom Triangle Cushion Covers?

The Triangle Is the Side View

This shape is all profile: vertical back, flat base, one long slope. The two triangular side panels are cut as an identical pair from your height and width, which is what keeps that profile crisp instead of drifting soft.

One Clean Slope to Lean On

The hypotenuse face is a single panel — no seam crossing the surface your back actually uses. It pulls taut from the top edge to the base, so the recline feels smooth end to end.

A Point That Stays a Point

Where the slope meets the base, the foam narrows to almost nothing — the spot cheap covers ball up and round off. A sewn seam runs that meeting edge instead, holding the wedge's sharp front line.

The Recline Sun Can't Bleach

A sloped face catches more direct sun than any flat cushion around it. Solution-dyed fabric holds its color through that exposure, and Horizon's waterproofing keeps surprise showers out of the foam.

Loading Happens Along the Base

The zipper spans the base's rear edge, where the opening is widest and the hardware is invisible. The foam wedge slides in point-first and seats itself into both side panels.

Step-by-Step Measuring Guide

• Slip the foam wedge out of its old cover and stand it as it leans in use — back vertical.

• Measure the height straight up the vertical back panel.

• Measure the width along the base, from the front point back to the rear edge.

• Measure the length of the run, end to end.

• Read the three numbers back off the foam before ordering — height and width together set your recline angle.

Fabric Information

Look at a triangle cushion from the side and you see the whole design: a right-triangle profile with a vertical back, a flat base, and one long slope connecting the top of the back to the front of the base. The cover is built from that profile — two triangular side panels cut as a matched pair, a back panel at your height, a base panel at your width, and the slope face spanning between them, all running your stated length. Get the two side triangles identical and the slope lies flat; that is the entire craft of this shape.

The slope is the working surface — it is what backs lean against and legs rest on — so the fabric face matters more here than on a cushion that only gets sat on. Sunbrella Horizon brings the marine-grade, fully waterproof vinyl for wedges that live on open patios and pool decks; Sunbrella Canvas brings the softer woven acrylic for shaded lounges where the wedge touches bare skin for an hour at a time. Both carry Sunbrella's 5-year limited warranty.

The zipper hides along the rear of the base — the one face that never shows and never gets leaned on. Corrosion-resistant YKK coil under a flap, so the hardware outlasts the seasons the wedge spends outside.