---
title: "Bay Window Cushion Fastening: Ties, Non-Slip Base or Zipper?"
url: "https://cushionguide.com/readings/faceted-denim-blue-bay-cushion-victorian-terrace/"
section: "Readings"
author: "Nate Kowalski, The Pattern Engineer of Detroit"
author_url: "https://cushionguide.com/masters/nate/"
published: "2026-08-26"
updated: "2026-09-24"
keywords: "bay window cushion, bay window seat cushion, angled window seat cushion, window seat cushion, reading nook cushion, made to measure cushion"
---

# A faceted denim blue bay window cushion, taken apart at the fastenings

*Nate draws a cross-section of a three-sided bay cushion in a Victorian row house and works out what holds it down, where the zipper goes, and what to label on the drawing.*

> **The quick answer:** A bay window cushion on a solid paneled seat should get a non-slip base, not ties, because there is no rail to tie to. Put the zipper along the back edge against the glass, wrapping the corners if the foam is thick. A non-slip base makes the cushion one-sided, so draw the shape as seen from above.

![Denim blue faceted bay window seat cushion on a white paneled base with linen and check pillows and a brass lamp](https://cushionguide.com/media/bay-window-cushions/faceted-denim-blue-bay-cushion-victorian-terrace-1600.webp "A denim blue cushion shaped to a three-sided bay, with pillows and a brass lamp gathered at the reading end.")

## Three sashes, several facets, zero rails to tie a bay cushion to

Here is the first measurement that matters on this seat: the number of things you can tie a cushion to. Zero.

The photograph shows a three-sided white bay with sash windows over a row-house street. The seat below is a paneled box. A denim blue [bay window cushion](https://cushionguide.com/cushions/bay-window-cushions/) follows every facet, so no bare board shows and the paneling is framed by one clean line of blue. Box edge, self piping. Angles are just lengths in disguise, and this cushion got its lengths right.

The styling is pushed to the right-hand end. Two ivory linen pillows and a cream tartan-check pillow sit beside a brass arc lamp, raised on stacked books to shoulder height. That end is the reading seat; the rest of the view stays clear. A blue and sand Persian rug repeats the cushion color at floor level, and the herringbone oak picks up the sand.

The fabric is a denim blue [performance weave](https://cushionguide.com/fabrics/performance-and-pet-friendly/), one solid color. In a bay the window shape is already the pattern, so one solid plus one patterned pillow is the right ratio.

Now the fastenings, partner. A cushion this shape creeps toward the glass every time someone leans back. What holds it? The long answers live in the Patterns on [ties, grip and Velcro](https://cushionguide.com/guides/stop-bench-cushion-sliding-ties-nonslip/) and [zipper placement](https://cushionguide.com/guides/cushion-zipper-placement/). The short answers are below.

## Pinned by Nate: five coordinates on the bay

Five pins map the bay from the faceted cushion to the rug, each one marked with the job it does.

1. **Denim blue bay cushion**: The cushion follows every facet of the bay so no bare board shows.
2. **Ivory linen pillows**: Pillows gather on the right, near the lamp, marking the reading end.
3. **Tartan-check pillow**: A soft check adds pattern without competing with the rug.
4. **Brass lamp on books**: Stacked books raise the lamp to shoulder height for reading.
5. **Persian rug**: Blue in the rug repeats the cushion at floor level.

## Cross-section: four fastening decisions, top to bottom

1. **Ties only with something to tie to**: Ties knot to spindles, rails or a frame. Four corner ties hold a bench cushion from below; two at the back corners suit a chair. A paneled box has none of those, so ties here would just hang.
2. **A non-slip base for a solid box**: A grippy fabric sewn to the underside holds the cushion on smooth painted or wood tops. Ask whether that grip layer washes with the rest of the cover.
3. **One-sided means drawn from above**: With a non-slip base the cushion has a top and a bottom. Label the drawing as viewed from above, or an angled shape can arrive mirror-imaged.
4. **The zipper on the back edge**: Set the zipper on the edge that faces the glass. On thick foam it wraps one or both corners so the foam goes in without crushing them. A tufted cushion can't take a removable zippered cover at all, because the tufts pass through the filling.

## Two angled ends, a marigold stripe, and a 26⅜ in check

A buyer sent the workshop a drawing and a photo of a window seat with two angled ends. The shop pointed them to the trapezoid listing, since that is what the shape is.

The choices took longer than the geometry. They went back and forth between two striped yellows, hoping for marigold rather than bright yellow, and between horizontal and vertical stripes. They settled on vertical stripes with matching piping, like a reference image they liked.

After sewing, the shop measured the slanted sides at 26⅜ in (67 cm) and sent photos for approval before shipping. The buyer approved. On a trapezoid the front, the back and the depth fix the angled sides, so that measured photo is the real test. The [bay window calculator](https://cushionguide.com/studio/bay-window-calculator/) runs the same arithmetic before you order.

Does your bay seat have a rail, a lip, or nothing at all?

## Buyer questions: long seats, sketches, trapezoids

**A common question:** My window seat is 29⅛ in (74 cm) deep and 122 in (310 cm) long. Can you make tufted cushions for it in two or three pieces?

**The workshop's answer:** Yes. The shop made two tufted linen cushions, each 29⅛ x 61 in (74 x 155 cm), to cover the 122 in seat, with the linen chosen by its color number. The order shipped the next day and delivery took 3 to 5 days.

**A common question:** What's the best way to send measurements for an L-shaped or oddly shaped bench?

**The workshop's answer:** Photos plus a hand-drawn sketch with every dimension written on it. If a photo or file is hard to read, the shop asks for the sizes drawn by hand. For complex pieces it sends back its own measurement drawing for you to confirm before production starts.

**A common question:** How do I measure a trapezoid window seat? Do I need a template?

**The workshop's answer:** A simple drawing with every edge measured is enough, and the shop can send template examples and another buyer's order drawing to copy. A photo of the seat helps too. The depth and length you pick on the listing, such as 28 in (71 cm) and 88 in (224 cm), only set the price; the trapezoid listing asks you to upload your drawing at checkout.

## On the cutting table: the faceted bay cushion

|   |   |
|---|---|
| Product | Faceted bay window seat cushion |
| Fabric | Denim blue performance weave |
| Edge | Box edge |
| Piping | Self piping |
| Fastening | Non-slip base; no rail to tie to |
| Zipper | Back edge facing the glass, wrapped at the corners for thick foam |
| Drawing | Seat viewed from above, every edge labeled |
| Check | Angled sides measured after sewing, photo approval before shipping |
| Best for | Three-sided bays in older homes |

> A paneled bay seat has nothing to tie a cushion to. Ask for a non-slip base instead, and draw the shape as seen from above so it doesn't arrive mirrored.
>
> — Nate

> **Tailor's margin:** A non-slip base makes a one-sided cushion. Write viewed from above on your drawing, right beside every angled edge.

## Questions buyers ask next

### Can I use ties on a bay window cushion?

Only if the seat has a rail, spindles or a frame edge to knot them to. On a solid paneled or boxed seat, ties hang loose and do nothing; a non-slip base on the underside holds the cushion far better.

### Why draw a non-slip cushion as seen from above?

The grip layer goes on one face only, so the cushion can't be flipped. If the drawing is ambiguous, an angled shape can be made as its mirror image. Label it viewed from above and mark which edge faces the window.

### Which edge of a bay window cushion should carry the zipper?

Along the back edge, against the glass or wall, where it stays out of sight. On thick foam it often wraps around the corners so the foam slides in without crushing them. A hidden zipper tucks the teeth under a fold.

### Can a tufted window seat cushion have a removable cover?

No. The tufts pass through the filling, so the cover can't be zipped off and washed on its own. If washability matters more than buttons, choose a plain cushion with a zippered cover instead.

## Related at the atelier

- [Bay Window Cushion for a Dog: Denim Blue, Cut to Every Facet](https://cushionguide.com/readings/denim-blue-bay-window-cushion-golden-retriever/): A bay window seat cushion feels generous when it is cut to the bay's own angles, edge to edge, instead of stopping square short of the returns.
- [Bay Window Cushion in Denim Blue: The Self-Piping Decision](https://cushionguide.com/readings/denim-blue-trapezoid-bay-seat-golden-retriever/): On a trapezoid bay window cushion, self piping is the forgiving choice: the welt matches the body, so a small angle miss at the wall doesn't get a line drawn to it.
- [Bay Window Cushion in Terracotta: Reading the Self-Piping Line](https://cushionguide.com/readings/terracotta-bay-window-seat-cushion-tabby-cat-parquet/): On a bay window cushion, self piping keeps the eye on the whole shape, while contrast piping outlines every angle and cut-in.
- [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…
- [The size menu only asks for width and length. What do I pick for a trapezoid cushion?](https://cushionguide.com/answers/trapezoid-cushion-size-selection-width-length/): Pick the size range that covers your trapezoid's longest side and its deepest depth; that choice only sets the price.
- [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.
- [5-sided bay window cushions: working out angles, sections and seams](https://cushionguide.com/guides/5-sided-bay-window-cushion-calculator/)

*± 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/faceted-denim-blue-bay-cushion-victorian-terrace/