Opacity is the single most important spec on any window covering — and the one most often misunderstood. It describes how much visible light a fabric or slat blocks when the shade is closed. Every fabric sample you see falls into one of four opacity tiers, and picking the wrong tier is the number-one reason customers end up disappointed after installation.
The four tiers are sheer , light filtering (also called translucent or semi-transparent), room darkening , and blackout . Every roller, cellular, roman, drapery, sheer horizontal (Silhouette), and zebra shade is built on one of these four opacities — regardless of brand or price.
Sheer fabrics diffuse harsh direct sun into a soft, even glow while keeping your view mostly intact. Think of them as sunglasses for the window — you still see out clearly, but glare and UV are cut. Openness factors on true sheers run 10–20%, meaning 80–90% of the fabric is open weave.
Where sheers win: south- and west-facing living and dining rooms where you want the view all day, formal spaces where the fabric itself is decor, and any room where you'll add a second layer (like drapery) for evening privacy.
The catch: at night, when interior light is brighter than outside, sheers reverse — anyone standing outside can see silhouettes clearly. Never use sheers alone in bedrooms, bathrooms, or ground-floor rooms without a second layer.
Light filtering (sometimes labelled translucent or semi-opaque) is the most popular opacity in Canadian homes for a reason. It blocks 30–70% of light, filters harsh direct sun, and gives you daytime privacy — people outside see only vague shapes, not detail. Solar shades in the 3–10% openness range fall here, as do most standard cellular shades and light-filtering rollers.
Opacity describes how much light a fabric or slat blocks. The four common levels are sheer (10–30% light block), light filtering / translucent (30–70%), room darkening (85–95%), and blackout (99–100%).
Room darkening fabric blocks 85–95% of light but usually leaks around the edges of the window. True blackout blocks 99–100% at the fabric — and only delivers total darkness when paired with side channels or a generous outside-mount that seals the edges.
No. Sheer and most light-filtering fabrics reverse at night: when it's brighter inside than outside, people can see silhouettes. For 24-hour privacy in bedrooms and bathrooms, layer a sheer with a blackout, or choose a zebra / dual shade that toggles between the two.
Blackout for the sleep surface (behind the bed) with side channels or reverse-roll to seal edge light. Many clients layer a light-filtering shade for daytime use with blackout drapery or a blackout roller as the primary sleep layer.
Light filtering or a 3–5% solar shade for daytime — you keep the view and cut glare on the TV without darkening the room. Layer with drapery for evenings.
Yes. Blocking 99–100% of direct sun eliminates the radiant heat gain through the window, which is a major contributor to summer overheating on south- and west-facing glass.