---
title: "Bay Window Cushion in Deep Teal: A Three-Sided Bay Makeover"
url: "https://cushionguide.com/readings/deep-teal-trapezoid-cushion-white-bay-window/"
section: "Readings"
author: "Nate Kowalski, The Pattern Engineer of Detroit"
author_url: "https://cushionguide.com/masters/nate/"
published: "2026-04-16"
updated: "2026-09-24"
keywords: "bay window cushion, bay window seat cushion, trapezoid bench cushion, angled window seat cushion, window seat cushion, custom size cushion"
---

# One deep teal cushion turns a white three-sided bay into a seat

*Before: a painted ledge under three windows. After: a place to sit. Between the two sits one cushion and a short list of honest measurements.*

> **The quick answer:** A bay window cushion should follow every side of the bay, with a straight center run on the back wall and angled wings cut to the splay, and each angle measured separately because very few bays are symmetrical. Deep teal on white paneling anchors a wall that is mostly glass, and a box edge with no piping keeps the angled corners clean.

![Deep teal chenille trapezoid cushion fitted to a white paneled bay window seat with sheer linen curtains and oak floor](https://cushionguide.com/media/bay-window-cushions/deep-teal-trapezoid-cushion-white-bay-window-1600.webp "A shaped teal cushion follows all three sides of a period bay window. White paneling and sheer linen keep the look crisp.")

## Notebook, page one: the bay before the cushion

Before, this bay was three windows over white panels and a ledge nobody sat on. Overcast light came through the sheer linen and turned the whole wall into one pale sheet. Bright, cool, a little empty.

The brief I wrote in the notebook had three lines. Make it a seat. Give the glass wall a floor. Keep it calm.

After, one [bay window cushion](https://cushionguide.com/cushions/bay-window-cushions/) does all three. Deep teal is dark enough to anchor a wall that is mostly window, and its petrol-green undertone picks up the eucalyptus in the cream vase. The oak floating shelf and the oak boards keep the white from going clinical. The sheers stay on every sash, softening the light without blocking the view. The oatmeal wool rug is there so bare feet land on something warm.

The cushion depth lines up with the paneled plinth below, so seat and base read as one piece of joinery. There is no piping; on angled wings a welt would have to turn two sharp corners, and a plain box edge keeps those turns clean. The chenille belongs to the [jacquard and damask family](https://cushionguide.com/fabrics/jacquard-and-damask/).

Notice what is not on the seat: nothing. Good for a photograph. For daily life I'd add one pillow at each corner, where the wings meet the center run.

## Pinned by Nate: five points on the bay

Five pins: the straight center run, both angled wings, the white paneled base and the eucalyptus that sets the green.

1. **Straight center run**: The center section takes the back wall while the wings are cut to the splay of the bay.
2. **Left angled wing**: The side follows the bay angle, so there is no gap or overhang at the corner.
3. **Right angled wing**: Measure each angle separately; very few bays are perfectly symmetrical.
4. **Eucalyptus vase**: Silver-green eucalyptus picks up the green undertone of the teal.
5. **White paneled base**: White panels under a deep teal top give a clean, tailored contrast.

## The teal bay window seat, before and after

| Line item | Before | After |
|---|---|---|
| Seat | Bare paneled ledge | Trapezoid box cushion across all three sides |
| Glass wall | White on white in gray light | Deep teal anchoring the bay |
| Corners | Dead space where the sides meet | Wings cut to the splay, no gap, no overhang |
| Edge | Painted nosing | Plain box edge lined up with the plinth |
| Props | None | Eucalyptus, oak shelf, oatmeal rug |

## A seven-sided bay window cushion, typed out from A to G

A buyer in the US sent the workshop a sketch of an angled-top bay window. The drawing was hard to read, so the workshop asked for every side typed out as well. It came back as a list: A 4.3 in (11 cm), B 4.3 in (11 cm), C 78.5 in (199 cm), D 48 in (122 cm), E 24 in (61 cm), F 24 in (61 cm), G 23 in (58 cm).

Seven letters, seven numbers, no guessing. The cushion was made in velvet 131 Deep Navy Blue, a machine-washable fabric at 86°F (30°C).

The notebook lesson, partner: label every side with a letter and type the numbers as well as drawing them. The sketch shows the shape; the typed list is what gets cut. The [bay window calculator](https://cushionguide.com/studio/bay-window-calculator/) and the Pattern on [measuring a 3-sided bay](https://cushionguide.com/guides/bay-window-seat-cushion-3-sided/) are built on the same habit. How many sides does your bay have?

## Buyer questions: arcs, backrests and lead time

**A common question:** Can you make a curved wedge cushion for one section of a round rattan outdoor sofa?

**The workshop's answer:** Yes; curved and angled shapes are made regularly. Along with the outer arc of 43 1/4 in (110 cm), the inner arc of 16 7/8 in (43 cm) and two sides of 19 3/4 in (50 cm), the workshop needed the depth of the curve: the distance from the middle of a straight line across the inner edge to the arc, 11 3/8 in (29 cm), marked on a sketch. The buyer ordered one cushion first to test the fit.

**A common question:** What size are your standard back pillows, and what do you need from me to price them?

**The workshop's answer:** The standard backrest is 15 3/4 in (40 cm) high and about 4 in (10 cm) thick. So the workshop needs only the length of each pillow and how many you want, then confirms the price.

**A common question:** How long does a custom bench cushion take from order to my door?

**The workshop's answer:** Production time depends on the job, and some custom jobs take longer; ask for it in writing. Delivery time comes on top of that; for one buyer who asked, it was quoted at 2 to 4 business days after dispatch.

## On the cutting table: the teal bay

|   |   |
|---|---|
| Cushion | Trapezoid box cushion: straight center run with two angled wings |
| Fabric | Deep teal chenille with a petrol-green undertone |
| Piping | None |
| Fit | Wings follow the bay angle, with no gap or overhang at the corners |
| Angles | Measured one at a time; left and right rarely match |
| Depth | Lines up with the paneled plinth below |
| Sketch | Every side lettered, every number typed as well as drawn |
| Styling | Eucalyptus, oak shelf, oatmeal rug; a pillow at each corner in daily use |
| Best for | Bright period bays with white paneling |

> Very few bay windows are perfectly symmetrical. Measure the left and right angles one at a time, or the cushion wings will stop short of the corners.
>
> — Nate

> **Tailor's margin:** Letter every side of the bay, A to G, and type each number under the sketch. A drawing shows the shape; the typed list gets cut.

## Questions buyers ask next

### Why choose a dark cushion for a bright bay window?

A dark color such as deep teal anchors a wall that is mostly glass and frames the view instead of competing with it. On white paneling it reads crisp and tailored, and it keeps its depth in cool overcast light.

### How do I record the sides of an angled bay for a custom cushion?

Give every side a letter on your sketch, then type each length beside its letter, measuring left and right separately. Angles are just lengths in disguise: with every side written down, the shape can be drawn true.

### Where do pillows go on a three-sided bay window seat?

One at each corner, where the angled wings meet the center run. The corners work as natural backrests, and keeping the middle clear leaves both the view and the cushion's shape easy to read.

## Related at the atelier

- [Three-Piece Bay Window Cushion in Teal: Reading the Angled Joints](https://cushionguide.com/readings/teal-three-piece-bay-cushion-angled-joints-closeup/): A bay window cushion is usually made in three pieces: a center trapezoid and two angled wings that butt together on each corner of the bay.
- [Bay Window Cushion in Three Pieces: Cream and Rust Jacquard](https://cushionguide.com/readings/three-piece-cream-rust-dash-bay-window-cushion/): A cream jacquard with a small woven rust dash is a forgiving choice for a bay window seat cushion: the pattern is part of the weave, so it won’t rub off, and small marks disappear into it.
- [Bay Window Cushion in Black and Cream Geometric Jacquard](https://cushionguide.com/readings/black-cream-geometric-bay-window-cushion-copenhagen/): A bay window cushion makes the biggest change when it is the only strong pattern in a pale room and stays slim, so the windows remain the tallest element.
- [Measuring a 3-sided bay window seat cushion, panel by panel](https://cushionguide.com/guides/bay-window-seat-cushion-3-sided/): Measure a 3-sided bay window seat cushion as a center panel plus two angled wings, taking every number from the trim face: the back edge of each panel, the full front edge, the depth at both ends of…
- [Bay window seats in Victorian houses, one cushion at a time](https://cushionguide.com/concepts/victorian-bay-window-seat-cushions/): A Victorian bay window seat cushion is a custom trapezoid, cut from a drawing that shows every edge, the straight depth and, in an old house, both diagonals.
- [Craftsman window seat cushions for shallow bays and short returns](https://cushionguide.com/concepts/craftsman-bungalow-window-seat-cushions/): A craftsman window seat cushion is usually a clipped trapezoid: a long front edge, a shorter back edge, and a short straight return at each end before the angled sides begin.
- [How to measure a trapezoid cushion so the numbers close](https://cushionguide.com/guides/trapezoid-cushion-measurements/)

*± 1/4 in — Nate*

---

Written by Nate Kowalski (https://cushionguide.com/masters/nate/) 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/readings/deep-teal-trapezoid-cushion-white-bay-window/