---
title: "Trapezoid Cushion Zipper: Put It on the Short Back Edge"
url: "https://cushionguide.com/answers/trapezoid-cushion-zipper-placement/"
section: "The Cutting Table"
author: "Élodie Marchand, The Colorist of New Orleans"
author_url: "https://cushionguide.com/masters/elodie/"
published: "2026-06-10"
updated: "2026-06-10"
keywords: "trapezoid cushion zipper, trapezoid chair pad, cushion zipper placement, tapered dining chair cushion, removable cushion cover"
---

# Where does the zipper go on a trapezoid cushion, and will the foam come out?

*A trapezoid chair pad shows its long front edge to the whole kitchen. Keep that edge quiet and let the zipper live at the back, where only the chair rails see it.*

Also asked as: Keep the zipper in the back?; Will the foam be hard to remove to wash?

> **The quick answer:** Ask for the zipper on the shorter back edge and the workshop puts it there, so the long front edge stays clean. The zipper is sized to the shape and the workshop inserts the foam itself, so the foam slides in and out for washing even when the front is wider than the back. Send the back width, front width and depth.

![Mustard dotted chenille trapezoid cushion with terracotta velvet piping on an oak bay seat under three arched windows](https://cushionguide.com/media/bay-window-cushions/mustard-trapezoid-bay-seat-terracotta-piping-arched-windows-1600.webp "Terracotta velvet piping traces the angled ends of the mustard seat and ties it to the tiled floor.")

## Key facts

- The zipper can go on the shorter back edge on request.
- The workshop sews the cover and inserts the foam itself.
- Zipper length is matched to the shape, so the foam comes out for washing.
- A trapezoid pad needs back width, front width and depth.
- A sample drawing: 15 in (38 cm) across the back, 18 3/4 in (47.6 cm) across the front.

## Your trapezoid drawing, checked before you upload

- ✓ Back width, the short edge against the chair back, such as 15 in (38 cm)
- ✓ Front width, the long edge at your knees, such as 18 3/4 in (47.6 cm)
- ✓ Depth, measured straight from the back edge to the front edge
- ✓ Every edge labeled, so a note like 'zipper on edge D' can't be misread
- ✓ One written line: zipper on the shorter back edge
- ✓ Your fabric code, plus piping if you want it

## Why the zipper belongs at the back

The eye sits down first, and on a dining chair it lands on the front edge. On this rush-seat chair the terracotta pad reads as one warm line of clay and rust; a zipper there would draw a seam of metal teeth across the most visible inch. At the back, tucked against the ladder rails, it disappears.

The practical worry is the foam. When the front is wider than the back, will the slab squeeze through a short opening? The workshop answers that by sizing the zipper to the shape and inserting the foam itself before the pad ships, so it comes out for washing and goes back in. Label your edges, my friends, and write the request in your note. Which edge of your chair does the room see first?

For the measuring, see [trapezoid cushion measurements](https://cushionguide.com/guides/trapezoid-cushion-measurements/) or let the [trapezoid cushion calculator](https://cushionguide.com/studio/trapezoid-cushion-calculator/) do the arithmetic. Openings on every shape are covered in [cushion zipper placement](https://cushionguide.com/guides/cushion-zipper-placement/), and more tapered pads live under [dining chair cushions](https://cushionguide.com/cushions/dining-chair-cushions/).

## What to leave out of the note

- ✗ A single width for a pad that tapers
- ✗ A zipper on the long front edge, unless you want it seen
- ✗ Worry about wrestling the foam: the zipper length is matched to the shape

> **Tailor's margin:** Write 'zipper on the short back edge' on a trapezoid cushion drawing, right beside the back width, front width and depth.

> A trapezoid cushion zipper belongs on the shorter back edge: the long front edge stays clean, and the foam still slides out for washing.
>
> — Élodie Marchand

## Buyer questions

**A common question:** On a trapezoid chair cushion, where does the zipper go, and is the foam hard to get out for washing?

**The workshop's answer:** No need to worry. The workshop sews the cover and inserts the foam itself, placing and sizing the zipper so the foam slides in and out easily, even when the front is wider than the back. Upload a drawing with back width, front width and depth.

**A common question:** Can the zipper sit on the short side of my trapezoid pad?

**The workshop's answer:** Yes. On request it goes on the shorter back side, for example the edge marked D on your drawing, so the long front edge stays clean. Add it to the drawing or your note.

**A common question:** Could I buy empty zippered covers for tufted cushions and fill them myself?

**The workshop's answer:** Yes, as plain non-tufted zippered covers in your sizes. Tufted cushions are sold filled only, because the tufting goes through the filling.

**A common question:** Can you make a washable zippered cover for a crib mattress play mat?

**The workshop's answer:** Yes. Fully zippered, machine-washable box covers are made for play mats and crash pads up to at least 61 x 61 x 10 in (155 x 155 x 25 cm), with a long zipper for easy removal. Give the exact size and fabric code.

## Questions buyers ask next

### Does a trapezoid chair pad arrive with the foam already inside?

Yes. The workshop sews the cover and inserts the foam before the pad ships, so it arrives ready for the chair. When you wash the cover later, the zipper on the back edge is long enough for the foam to come out.

### Which three measurements does a trapezoid pad need?

The back width, the front width and the depth from back to front. A drawing with those numbers, such as 15 in (38 cm) across the back and 18 3/4 in (47.6 cm) across the front, is what the cover is cut from.

### Do I have to ask for the back-edge zipper?

Yes, write it on the drawing or in the order note. On request the zipper goes on the shorter back edge, and naming that edge by its label on your drawing removes any doubt about which side is which.

## Related at the atelier

- [Can I choose which side the zipper goes on?](https://cushionguide.com/answers/choose-zipper-side-cushion-cover/): You can choose which edge of a custom cushion cover the zipper is sewn on.
- [Where does the zipper go on my cushion, and will it show?](https://cushionguide.com/answers/cushion-cover-zipper-placement/): The zipper goes on the cushion's back edge, the one against the wall, window or chair back, or on the underside, and it comes standard on every cover at no extra charge.
- [Chair Cushion with Ties: What's Inside a Velvet Bistro Pad](https://cushionguide.com/readings/burgundy-velvet-rattan-bistro-chair-pad-blush-piping/): A chair cushion with ties for a rattan bistro chair should be a firm, fairly thin pad cut from a paper template, thick enough to cover the woven rim but not so soft it spreads.
- [Chair Cushion with Ties: The Foam Inside Indigo Ticking](https://cushionguide.com/readings/indigo-ticking-stripe-kitchen-chair-cushion/): A kitchen chair cushion for a hard ladder-back seat works best as a box-edge pad that keeps its full thickness right to the front rail, cut to the seat and not past it.
- [Chair Cushion With Ties: Teal Velvet Box Pad, Front View](https://cushionguide.com/readings/teal-velvet-box-cushion-front-view-gusset/): A chair cushion with ties is easiest to judge from a straight-on photo: the front gusset shows its height against the seat rail, and the top welt must run level from corner to corner.
- [Velvet seat cushions: how the pile catches the light on a chair](https://cushionguide.com/guides/velvet-seat-cushions/): A velvet seat cushion from the workshop is 4 in (10 cm) thick as standard, or 2 in (5 cm) as a tie-on chair pad, cut to your exact seat in short-pile polyester velvet with piping included.
- [Cushion zipper placement: back edge, underside and odd shapes](https://cushionguide.com/guides/cushion-zipper-placement/)
- [How to measure dining chairs for seat pads with ties](https://cushionguide.com/guides/dining-chair-pad-measurements/)

*With color and care — Élodie*

---

Written by Élodie Marchand (https://cushionguide.com/masters/elodie/) for CushionGuide (https://cushionguide.com/about/). The site explains made-to-measure cushions and the partner workshop makes them; measurements are in inches first. This Markdown mirrors the page at https://cushionguide.com/answers/trapezoid-cushion-zipper-placement/