---
title: "Window Seat Cushion Fading: Fabric for Sun Through Glass"
url: "https://cushionguide.com/guides/window-seat-cushion-fading-sun/"
section: "The Pattern Room"
author: "Élodie Marchand, The Colorist of New Orleans"
author_url: "https://cushionguide.com/masters/elodie/"
published: "2026-07-30"
updated: "2026-09-24"
keywords: "window seat cushion fading, fabric fading in sun, lightfastness blue wool scale, fade resistant cushion fabric, cushion fabric uv"
---

# Will a window seat cushion fade? Choosing fabric for sun through glass

*A window seat is the one indoor cushion that sunbathes every day, through glass that stops the rain but not the light. Here is how a colorist chooses the fabric, the tone and a few small habits so spring's navy is still navy by Thanksgiving.*

> **The quick answer:** A window seat cushion can fade gently over the seasons when hours of direct sun reach it through the glass, so choose a fabric rated 6 or higher on the 1-to-8 blue wool lightfastness scale, or a sun-resistant outdoor fabric for full sun. Ask for the same fabric on both faces, flip and rotate it each season, and draw a sheer curtain at midday.

![Navy corduroy window seat cushion on a pine paneled base with brown floral wallpaper, mustard curtains and rattan pendant](https://cushionguide.com/media/window-seat-cushions/navy-corduroy-window-seat-floral-wallpaper-rattan-1600.webp "Navy corduroy cools a room full of mustard, pine and brown florals. Hung low over the seat, the rattan pendant marks it as a spot of its own.")

## Glass keeps out the rain, not the light

Glass keeps out the rain, not the light. A window seat takes daily UV through the pane, and over a few seasons a saturated color can soften where the sun lands while it stays rich where the curtain throws shade. That uneven line is what people notice, far more than the fading itself.

Window seat cushion fading is the part of the order almost nobody plans for. Buyers send the workshop careful measurements, a piping color, even a photograph of the rug, and seldom a word about which way the window faces. Yet most lightfastness advice is written for patios, not for [window seats](https://cushionguide.com/cushions/window-seat-cushions/) and bay windows that sit behind glass all year, or for a bright [sunroom](https://cushionguide.com/cushions/sunroom-cushions/).

The navy corduroy seat at the top of this page shows the other half of the answer: mustard curtains on either side, ready to be drawn when the afternoon comes in hot. Fabric does most of the work. Habits do the rest.

## Choosing a window seat fabric for sun, step by step

1. **Watch where the sun lands for one day**: Before you choose a swatch, note which way the window faces and how many hours direct sun sits on the seat itself, not just in the room. The indoor fabrics carry some UV resistance and suit most window seats. A seat that takes strong, direct sun for long hours is where the sun-resistant outdoor range earns its place.
2. **Ask for the lightfastness number**: [Lightfastness](https://cushionguide.com/glossary/#lightfastness) is graded on the blue wool scale from 1 to 8, and each step takes roughly twice the light of the one below. Under test lamps, level 1 shows a fade after about 3 hours and level 8 after about 384. Read 6 as good and 7 or 8 as excellent, and compare only results from the same test: ISO 105-B02 and AATCC 16 numbers don't translate.
3. **Know where the color lives in the fiber**: In a [solution-dyed](https://cushionguide.com/glossary/#solution-dyed-acrylic) fabric, pigment goes into the polymer before the fiber is spun, so color runs through the whole cross-section. Solution-dyed acrylic grades about 7 to 8 on the blue wool scale, against 5 to 6 for most performance polyesters and olefins. Once you've picked a code, ask for its UV rating; it varies from fabric to fabric.
4. **Choose a tone that forgives the light**: Fading reads as contrast, so the colors that shout lose the most face. Jet black, clear primaries and deep jewel tones show a sun line quickly. Mid-tones with a little gray in them, such as sage, oatmeal, taupe and washed denim, and weaves with a heathered or textured face, hide a gentle shift far better. More in [sunroom colors that last](https://cushionguide.com/concepts/sunroom-cushions-colors-that-last/).
5. **Ask for the same fabric on both faces**: A standard [box cushion](https://cushionguide.com/glossary/#box-cushion) wears the same fabric top and bottom, with piping on both edges, so it can be flipped. Keep it that way: a [non-slip base](https://cushionguide.com/glossary/#non-slip-base) replaces one face, and reversible cushions are made without it. On a shallow seat that might slide, ask for ties at the back instead.
6. **Flip and rotate with the seasons**: Turn the cushion over and end for end at each change of season, and swap identical pieces between the sunny and shady ends of a long seat. The sun then works both faces evenly, and any change stays soft instead of drawing a line where the curtain falls.
7. **Filter the midday hours**: Sheer curtains, a linen blind or lined drapes drawn during the strongest hours cut the dose without darkening the room. Move throw pillows and a folded throw around now and then, or the patch beneath them stays darker than the seat around it.
8. **Keep velvet out of the long sun**: [Velvet](https://cushionguide.com/fabrics/velvet/) should be kept out of prolonged direct sun, and pile plays its own tricks: pile direction can make an off-white read darker or beige, which is normal shading, not lost color. For a bay that bakes all afternoon, choose a flat weave from the sun-resistant range.
9. **Order the whole seat from one roll**: Sun-softened fabric and a brand-new cover will never match, and neither will two [dye lots](https://cushionguide.com/glossary/#dye-lot). Order the seat, its bolsters and its pillows together, keep the fabric code, and when the time comes, recover the whole set. The reasons are in [matching cushions later](https://cushionguide.com/guides/dye-lots-matching-cushions-later/).

## The blue wool scale, read for a window seat

| Blue wool rating | Test-lamp exposure before a visible fade | Where it belongs in a sunny room |
|---|---|---|
| 1 to 3 | From about 3 hours (level 1) to about a day | Pillows and trims kept away from the glass |
| 4 | About 40 to 48 hours | A seat in bright, indirect light |
| 5 | About 80 hours | A window seat that sees only morning sun |
| 6 | Graded good | A window seat with a few hours of direct sun |
| 7 to 8 | Graded excellent; level 8 at about 384 hours | A bay in strong sun for long hours, where solution-dyed acrylic sits |

## A black bay cushion, 160 inches long, for a sunny window

A buyer in the US wrote to the workshop about a very large trapezoid bay: a cushion about 160 in (406 cm) long and 2 ft (61 cm) deep, in black, and sun-resistant. Not corduroy, they added, and not velvet.

I liked that brief the moment I read it. Black is the least forgiving color in a sunny bay, because any softened patch shows as a grayed shadow beside the sheltered ends, and pile fabrics shift tone with the light anyway. The workshop confirmed it stocks sun-resistant fabrics, and a flat, sun-resistant black was the right family to choose from.

The length raised its own question. A single piece that long is hard to make, ship and lift, so the workshop suggested two. Two sections are also easier to flip and turn with the seasons, which a sunny seat needs. If your bay is a trapezoid too, the [trapezoid cushion calculator](https://cushionguide.com/studio/trapezoid-cushion-calculator/) will check the angles before you write in.

## Why the sun line matters more than the fade

Here is a thought that calms most buyers. A fabric that softens evenly is rarely noticed; what the eye catches is the edge where sun meets shade. Let one color speak and the others listen, and choose the speaker for the light it will live in.

That is why the habits matter as much as the fabric. A reversible cushion turned each season, curtains drawn at midday and pillows moved now and then keep any change even. Judge swatches at the window itself, not on a screen, because the light at the glass is the light your cushion will live in. The method is in [screen versus daylight](https://cushionguide.com/guides/cushion-color-screen-vs-daylight/), and humid glass rooms have their own notes in [sunroom fabric](https://cushionguide.com/guides/sunroom-cushion-fabric-humidity/).

So, my friends: which way does your window face, and how many hours does the sun sit on the seat?

## Common mistakes on a sunny window seat

- ✗ Choosing the fabric for looks alone. Tell the maker the seat faces the sun before you choose, so the color search starts in the right chart.
- ✗ Writing a color name instead of a code. Each color comes in several shades and neighboring numbers can differ only in tone; give exact codes for fabric and piping.
- ✗ Adding a non-slip base and then hoping to flip. The non-slip bottom takes one face; choose reversible, and ask for ties if the seat is shallow.
- ✗ Replacing one faded cushion on its own. A new cover beside a sun-softened one shows the difference at once; recover the set together.
- ✗ Leaving the same pillow in the same corner all summer. The fabric under it stays darker than the seat around it.
- ✗ Putting velvet in a bay that bakes all afternoon. Keep pile fabrics out of prolonged direct sun.

> **Tailor's margin:** Ask for the same fabric on both faces of a window seat cushion, then flip it at each change of season so the sun works both sides evenly.

> Blue wool 6 is good and 7 or 8 is excellent. For a window seat in hours of direct sun, ask for the lightfastness number before you fall for the color.
>
> — Élodie

## Protect the glass too

- ✓ UV-blocking window film on the glass behind the seat
- ✓ Solar blinds or sheer curtains drawn during the hardest afternoon sun
- ✓ Rotate and flip the cushion now and then to even out the sun line
- ✓ Choose steadier colors for the seat and keep bright accents on pillows
- ✓ Test a swatch in the window for a week or two, half covered, before ordering
- ✓ UV fabric sprays exist, but guides report uneven results

## Buyer questions: sun, glass and color

**A common question:** Will the fabric fade if my cushion sits in a sunny window?

**The workshop's answer:** The workshop's indoor fabrics hold up well by a sunny window and clean easily with gentle hand cleaning. The indoor fabrics have some UV resistance but aren't outdoor fabrics, so strong direct sun for long hours can soften a color a little over time. For a seat like that, the sun-resistant outdoor range is the more fade-resistant choice.

**A common question:** Is the fabric the same on both sides so I can flip the cushion over?

**The workshop's answer:** Yes. Both faces use the same fabric and the piping runs around the top and bottom edges, so the cushion can be flipped. If you add a non-slip bottom, that face changes, which is why reversible cushions are made without one.

**A common question:** My porch has a roof. Can I use regular indoor fabric out there?

**The workshop's answer:** Yes, if the roof is closed and neither rain nor direct sun reaches the seat; linen-look, velvet and the soft fabrics are fine there, though none is waterproof. The workshop checks that the area really is covered first. For a screened porch open to pollen, dust and humidity, or anywhere in the open air, choose outdoor fabric, and the workshop can send samples first.

**A common question:** Is a color name enough when I order, or do you need a code?

**The workshop's answer:** The workshop needs the exact code from the fabric charts in the listing photos, because each color comes in several shades, and it holds an order until it has one. Indoor and outdoor listings have separate charts. If you want a color you saw in a listing photo, say so in the order notes; you can still switch fabric before production starts.

**A common question:** The cushion in your photo looks lighter than the swatch. Is it a different fabric?

**The workshop's answer:** Send a screenshot of the exact photo and the workshop will name both the fabric and the piping codes. Sunlight and the camera angle can make a tone look slightly different, but it is the same fabric. For an older photo whose codes have changed, write 'same as the first picture' and the workshop will match it.

## Sunny window seat questions, answered short

### What does a blue wool rating of 6 mean for a window seat?

It means good lightfastness on a scale that runs from 1 to 8, where each step takes roughly twice the light of the one below. A 6 suits a seat with a few hours of direct sun; for long hours of strong sun, look for 7 or 8, the range where solution-dyed acrylic sits.

### Does a west-facing window seat need outdoor fabric?

Usually not. The workshop has told buyers a west-facing window seat is generally fine in the indoor fabrics, which carry some UV resistance. Save the sun-resistant outdoor range for seats that take strong direct sun for long hours, and keep the flip-and-rotate habit either way.

### Is velvet a poor choice for a bay window?

It depends on the sun. Velvet should be kept out of prolonged direct sun, and its pile shifts tone with the light, so an off-white can read darker or beige. In a bay with filtered light it is lovely; in one that bakes all afternoon, choose a flat, sun-resistant weave.

### If one cushion fades, will a new cover match the others?

Not quite. A fresh cover looks brighter than sun-softened fabric beside it, and a new roll can sit a shade apart from the first dye lot. Recover the whole seat at once, and keep your fabric code so the workshop can match as closely as the roll allows.

### Which cushion colors fade fastest in a sunny window?

Warm brights, meaning red, orange and yellow, are most often named as the fastest to fade, and 100% cotton fades faster than synthetics. Sources disagree about dark colors: one says they absorb more light and fade sooner, another lists navy and deep green among the steadiest. Whatever you choose, rotating and flipping the cushion evens out the sun line.

### How can I test a fabric for fading before I order?

Tape a swatch to the actual seat, in the window it will live in, and leave it for a week or two. Cover half of it with card so you can compare the exposed and protected halves side by side. Swatches of any code can be ordered, so test two or three candidates at once and pick the one that changed least.

## Related at the atelier

- [Window Seat Cushion in Navy Pinstripe: 4 Mistakes It Avoids](https://cushionguide.com/readings/navy-pinstripe-ivory-window-seat-cushion-garden-room/): On a white window seat, choose a cushion with a fine stripe rather than plain ivory: a navy pinstripe on ivory reads as texture from across the room yet gives the box edge a clear line.
- [Window Seat Cushion in a Sunroom: Periwinkle and Maroon Stripe](https://cushionguide.com/readings/periwinkle-maroon-stripe-sunroom-window-seat/): In a sunny garden room, a two-tone striped window seat cushion is a safer choice than one plain color: the stripe hides gradual fading and crumbs, and each color can answer something in the room.
- [Moss Green Corduroy Window Seat Cushion in a Garden Sunroom](https://cushionguide.com/readings/moss-green-corduroy-window-seat-garden-corner/): A window seat cushion on a drawer base needs a firm, box-cut foam block, because the hard top gives nothing back and the cushion carries all the comfort.
- [Sunroom cushions and three-season rooms: color that survives the light](https://cushionguide.com/concepts/sunroom-cushions-colors-that-last/): Sunroom cushions that sit in long, intense direct sun hold their color best in UV- and fade-resistant outdoor fabric.
- [Sunroom and three-season room cushions: fabric for sun, heat and damp](https://cushionguide.com/guides/sunroom-cushion-fabric-humidity/): For sunroom cushions, choose fabric for the room's harshest exposure: outdoor fabric where hours of direct sun, screened walls or regular damp reach the seat, and indoor velvet or smooth microfiber…
- [Custom cushions for Finnish summer cottages, apartments and lake terraces](https://cushionguide.com/places/custom-cushions-finland/): Custom cushions in Finland serve two lives: the city apartment with its glazed balcony, and the summer cottage, or mökki, by a lake with a sauna and a terrace.
- [Why mildew grows under a window seat cushion in winter, and what helps](https://cushionguide.com/guides/window-seat-cushion-mildew-condensation/)

*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/guides/window-seat-cushion-fading-sun/