---
title: "Bay Window Cushion, Curved and Black, in a Green Library"
url: "https://cushionguide.com/readings/curved-black-bay-seat-green-library-tuxedo-cat/"
section: "Readings"
author: "Nate Kowalski, The Pattern Engineer of Detroit"
author_url: "https://cushionguide.com/masters/nate/"
published: "2026-06-13"
updated: "2026-09-24"
keywords: "bay window cushion, bay window seat cushion, window seat cushion, reading nook cushion, pet friendly cushion, custom size cushion"
---

# A curved black bay window seat cushion, read for thickness and depth

*A cat asleep on a cushion is the most honest scale bar in a photograph. This one says the seat is deep and the pillows work harder than they look.*

> **The quick answer:** On a bay window seat cushion, thickness and depth trade against each other: each inch of cushion raises the seat an inch, and each back pillow takes its own thickness out of the depth. Four inches (10 cm) is the standard thickness, and 3 in keeps a window seat lower and neater. On a 23 in deep seat, 4 in back pillows leave 19 in to sit on.

![Curved black window seat cushion on an oak bay in a green library with a tuxedo cat, olive pillows and a brass arc lamp](https://cushionguide.com/media/bay-window-cushions/curved-black-bay-seat-green-library-tuxedo-cat-1600.webp "A curved black cushion follows an oak bay seat in a green library, with a tuxedo cat asleep on the bend.")

## The curve, the cat and the lamp

A curved oak bay, leaded glass, dark green walls, and one black cushion following the bend in a single sweep. The front edge was cut from a paper template of the seat, and black makes the curve read as one clean line.

Olive and oatmeal pillows alternate around the bend, so the eye travels the full length. The brass arc lamp leans over the far end, where the reader sits, and a small oak table there holds a book and a brass tankard, the only bright metal in the room. The tuxedo cat nearly vanishes on the black. Call that a vote for the fabric.

## Pinned on the photograph

Five pins around the bend, from the curved front edge to the lamp.

1. **Curved cushion front**: The front edge follows a smooth curve, cut from a paper template of the seat.
2. **Tuxedo cat**: A black-and-white cat almost vanishes on the black seat.
3. **Oatmeal pillow**: Oatmeal and olive pillows alternate around the bend.
4. **Brass arc lamp**: The lamp arches over the end of the seat where the reader sits.
5. **Side table**: A small oak table at the seat's end holds a book and brass tankard.

## Height and depth, in two sums

Seat height is platform height plus cushion thickness. Every inch of cushion raises the sitter an inch, so plan with the full number. The standard is 4 in (10 cm); 3 in keeps a window seat lower and trimmer.

Depth runs the other way. Standard back pillows are about 16 in (40 cm) tall and 4 in (10 cm) thick, and each one takes its thickness out of the seat. On a 23 in (58 cm) deep bay, that leaves 19 in (48 cm) to sit on: a real reading seat, not a ledge. How deep is your bay, wall to front edge?

Run your own numbers in the [seat height calculator](https://cushionguide.com/studio/seat-height-calculator/), and trace the curve the way the [curved cushion guide](https://cushionguide.com/guides/curved-cushion-chord-rise-radius/) shows. Angles are just lengths in disguise, partner. So are curves. More shapes live under [bay window cushions](https://cushionguide.com/cushions/bay-window-cushions/).

> Back pillows eat seat depth: on a 23 in deep bay seat, a row of 4 in thick pillows leaves 19 in to sit on.
>
> — Nate

## A nine-foot bay, sketched and quoted

A buyer sent a sketch of a trapezoid bay seat about 9 ft wide: a 107 1/2 in back edge, a 55 in front edge, two 32 1/2 in angled sides and a 23 in depth. The workshop quoted it and laid out the options: 2, 3, 4 or 5 in thick, piping in any color included, and a removable cover that washes at 86°F (30°C), no dryer. The price was more than the buyer had planned for.

I ran the sketch anyway. If that bay is symmetric, those edges and that depth want sides of about 34 7/8 in, not 32 1/2 in. Either the bay leans or a tape slipped, which is what the drawing check before cutting is for.

> **Tailor's margin:** Seat height is platform plus cushion. Swapping a 4 in cushion for a 3 in one lowers a window seat by 1 in.

## Sketches, stuffing and a quote

**A common question:** On my trapezoid sketch, which number do you follow: the depth, or the side length I wrote?

**The workshop's answer:** A 68 in top, a 110 in bottom and a 23 in depth give sides of about 31 in, not the 32 in on the sketch; a 1 in slip is common with hand measuring. The workshop asks which number to keep. Here the 23 in depth stayed, and the sides were cut at 31 in.

**A common question:** One backrest has a small rip and stuffing is coming out. What's inside?

**The workshop's answer:** Shredded foam, which the workshop finds lasts longer in use. Stray bits vacuum up easily, and a replacement cover was sent for the torn one.

**A common question:** If I send my measurements, can you quote a custom window seat cushion?

**The workshop's answer:** Yes. Send the sizes and the workshop replies with a price and a purchase link made for your order.

## On the cutting table

|   |   |
|---|---|
| Cushion | Curved bay window seat cushion, one piece, box edge |
| Fabric | Black performance weave |
| Piping | Self, in the same black |
| Thickness | 2, 3, 4 or 5 in (5 to 12.5 cm); 4 in (10 cm) standard |
| Foam | About 2.0 lb/ft³ (32 kg/m³), firm to medium-firm |
| Back pillows | Shredded foam in an inner cover, about 16 x 4 in (40 x 10 cm) |
| Care | Zipped cover, 86°F (30°C) gentle cycle, no dryer |

## Questions buyers ask next

### What thickness suits a bay seat used for long reading sessions?

Four inches (10 cm) is the standard most buyers keep. Three inches sits lower and neater, and 5 in (12.5 cm) is the deepest standard option.

### Can a curved window seat cushion be made in one piece?

Gentle curves, yes, from a paper template or a drawing marking the start, end, shallowest and deepest points. Strongly curved shapes may be declined, and one curved order was quoted at about 10 to 12 business days of making.

### Is a performance weave a good idea where a cat sleeps?

The pet-friendly chart includes a tightly woven polyester with no loops, which the workshop quotes at about 88,000 Martindale; it wipes clean and washes at 86°F (30°C). No fabric fully resists claws.

## Related at the atelier

- [Bay Window Cushion in Terracotta Diamond on a Stone Ledge](https://cushionguide.com/readings/terracotta-diamond-bay-window-cushion-tuscan-stone-alcove/): A bay window cushion on a solid stone or wood ledge works best slim and firm: about a third of the ledge height keeps the architecture in charge, and firm foam stops you feeling the hard base.
- [Bay Window Cushion with a Curved Front: The Piping Decision](https://cushionguide.com/readings/peach-curved-bay-window-cushion-tabby-cat/): On a curved bay window cushion, self piping is the safest choice: it holds the edge firm without drawing a colored line that exaggerates every small wobble in the curve.
- [Bay Window Cushion in Oatmeal Texture, Read Across the Seasons](https://cushionguide.com/readings/oatmeal-textured-angled-bay-seat-afternoon-sun/): An angled bay window cushion in oatmeal texture works year-round because it changes with the light, not with color.
- [Custom cushions for Michigan cottages, bungalows and bay windows](https://cushionguide.com/places/custom-cushions-michigan/): Custom cushions in Michigan split into two jobs: indoor bay window seats in brick bungalows and Tudors, and outdoor dock, deck and porch cushions at the cottage.
- [How do I order a cushion for an angled bay window seat?](https://cushionguide.com/answers/bay-window-seat-cushion-angled-order/): Order an angled bay window seat cushion on the trapezoid (custom-shape) listing, not the rectangle one, choosing the size by the seat's depth and overall length.
- [Cushions for 7-sided and rounded bay window seats in older homes](https://cushionguide.com/guides/7-sided-rounded-bay-window-seat-cushion/): A 7-sided bay window seat cushion is usually made as several angled sections, with a break at each corner, so every piece lifts out on its own.
- [Window seat dimensions and the cushion sizes that fit them](https://cushionguide.com/guides/window-seat-dimensions/)

*± 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/curved-black-bay-seat-green-library-tuxedo-cat/