A cornice is a hard built box, usually painted wood, with returns to the wall. A valance is a soft fabric panel hung across the top. A fascia is a slim L-shaped cover across the front and underside of the roller tube. A cassette is a fully enclosed headbox that the fabric rolls up into. The cornice and the cassette do the most about the light gap over the top of a shade; a fascia does some; a valance does the least, because it is decorative rather than structural.
The four, side by side
The four headers, in section
Cut through the head of the window and look sideways. Same shade every time; only the header changes.
| Made of | What it hides | The light gap at the top | Depth | The look | |
|---|---|---|---|---|---|
| Open roll | Nothing | Nothing — tube and brackets visible | Wide open | None | Minimal, modern, honest |
| Fascia | Aluminium or wrapped board | The tube from the room | Reduced | A little | Clean, commercial, repeatable |
| Cassette | An enclosed headbox | The tube on front, top and bottom | Meaningfully closed | More | Crisp and contemporary |
| Cornice | Built, painted wood | Tube, brackets and track | Closed | Most | Architectural, traditional, permanent |
| Valance | Fabric | The hardware, loosely | Little change | Varies | Soft, decorative, dressed |
The light-gap column is the one people have never thought about, and it is the reason this page exists.
Should you leave the roller exposed?
Honestly, often yes. An open roll is the cleanest, most minimal finish there is, it costs nothing extra, and it is genuinely the right answer in a lot of modern rooms — which is why it is the default almost everywhere.
It also leaks light over the top, collects dust on the exposed roll, and shows the brackets. So: fine in a living room; a poor idea in a bedroom or a nursery, where the top gap is exactly what wakes you at six in the morning.
Wood cornices
Why a workroom can build one and a catalogue cannot
A cornice is not a stocked part. It is a box cut to the opening, assembled with returns to the wall, filled, sanded and painted to match the trim in the room. Nobody can ship you one, because it does not exist until somebody makes it for your window.
That is also what it is for. A built cornice hides the tube, the brackets and the light gap in one move, and it lets a plain modern roller sit under traditional millwork without either of them looking out of place. We build them in the Akron workroom. Cornices, valances, cassettes and fascia.
What a header does that has nothing to do with light
Two things people discover afterwards.
Dust. An exposed roll is a horizontal fabric surface facing the ceiling, and it collects. In a kitchen it collects more than dust. A cassette closes the roll away and turns cleaning it from a job into nothing; a fascia helps; a cornice removes the question entirely.
The join between old and new. A roller shade is a modern object. In a room with substantial original casing, deep reveals and painted trim, an open roll sitting bare above a hundred-year-old window frame reads as an object added to the room rather than a part of it. A painted cornice made to the opening and matched to the existing trim is what closes that gap — not decoratively but structurally: it gives the shade a frame that belongs to the architecture.
That is also why a valance survives as a category despite doing very little about light. Sometimes the job at the top of the window is softening a room rather than darkening it.
Headers on a dual shade
Two tubes need a deeper header than one — so on a dual day-night shade the header is part of the design from the beginning rather than a decision made at the end. Dual day-night shades · The roller shade it covers.
Questions people ask
What is the difference between a fascia and a cassette?
A fascia is a slim cover across the front and underside of the roller, hiding the tube from the room but leaving it open at the back and top. A cassette is a fully enclosed headbox that the fabric rolls up into, closed on the front, top and bottom. The cassette costs you a little more depth and gives you back a cleaner finish, less dust on the roll, and a meaningfully smaller light gap at the top.
Is an open roll a bad idea?
Not at all — it is the most minimal look and it suits plenty of modern rooms, which is why it is the default. The trade-offs are real though: light comes over the top of the roll, dust settles on the exposed fabric, and the brackets are visible. In a bedroom or a nursery, where the top gap is exactly what wakes you up, we would put something over it.
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