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Solar Shade Openness Factor Explained: The One Number That Decides Everything

Saturday, August 29, 2026 — Wholesale Blind Factory

Openness factor is the one number that decides how a solar shade behaves: it's the percentage of the fabric that's open weave — literally the holes. A 1% openness fabric is a tight screen that blocks the most glare and heat and gives the most privacy; a 10% or 14% fabric is an airy mesh that keeps your view almost intact but lets more light and heat through. Every solar-shade decision — bedroom versus living room, view versus glare, privacy versus brightness — is really a decision about this number, so here's what it means in practice and how to pick.

What the number actually measures

Solar shade fabric is a woven screen, and openness factor is the share of its area that's open space between the yarns. Think of it as the fabric's aperture:

• 1–3% openness: tight weave. Strongest glare and UV control, best daytime privacy, most heat rejection — and the most muted view. The room reads dimmer and calmer.
• 4–5% openness: the all-rounder. Solid glare control, good view-through, comfortable brightness. If you're not sure, this is the range most living spaces end up loving.
• 7–10% openness: view-first. The screen almost disappears against the glass; glare and heat control are lighter-touch. Right where the view is the whole point.
• 14%+ openness: barely-there mesh for spaces that want a whisper of screening and maximum daylight.

Two fabrics with the same openness can still differ — colour matters, and we'll get to that — but openness sets the ceiling on what any solar fabric can do.

The view-through paradox (read this before choosing)

Here's the counterintuitive part that surprises almost everyone at the showroom: darker fabrics give better view-through. A dark 5% fabric reads like sunglasses — the weave visually recedes and the view pops. A white 5% fabric glows when sunlight hits it, scattering light like a lampshade and washing out the view. So:

• Want to keep the view? Choose a darker fabric — charcoal, bronze, black — at moderate openness.
• Want maximum brightness and a softer look? Lighter fabrics, accepting more glow and less view clarity.
• Want heat rejection above all? Lighter and metallic-backed fabrics reflect more solar energy; dark fabrics absorb heat (some re-radiates inward). For a west wall that bakes, a light or dual-sided fabric at low openness does the most work.

There's no single best — there's the best for what the window is for. This is exactly the trade-off we bring sample cards to demonstrate against your actual glass, because seeing it beats any chart.

Privacy: the day/night flip nobody should learn the hard way

Solar shades give daytime privacy only. During the day, the bright side is outside, so passersby see reflections while you see out. After dark the physics flips: your lit room becomes the bright side, and a solar shade — any openness — becomes see-through from the street. The tighter the weave the less visible you are, but no solar fabric is nighttime privacy. The honest specs for rooms that need evening coverage:

• Living rooms with a view: solar shade for the day, paired with drapes — or a dual roller with a privacy layer behind, as covered in our day-night combos guide.
• Bedrooms: solar alone is the wrong tool; blackout or a dual system is the answer.
• Street-facing home offices: 3% or tighter openness handles the workday; add a layer if you work late with the lights on.

Matching openness to BC rooms

• South and west glass in Vancouver: the summer heat problem. 3–5% in a heat-reflective colour tames the afternoon without losing the yard.
• The view condo: the classic case for 5% in charcoal — mountains intact, glare gone, and a white or light exterior backing where strata uniformity rules apply (a routine spec for us).
• Home offices: 3–5% dark fabric kills screen glare while keeping the room connected to outside — the reason solar shades own this category.
• North-facing rooms: glare is mild; choose openness for look and privacy rather than heat, and consider whether a light-filtering roller suits better.
• Sunrooms and big sliders: heavier sun loads justify tighter weaves; motorized operation (a natural Somfy pairing) makes big spans usable daily.

UV, furniture, and the honest fine print

Solar fabrics block the majority of UV even at higher openness — a 5% fabric stops most of what fades hardwood and upholstery — but the light and heat that make a room pleasant still enter by design. A solar shade slows fading dramatically; it doesn't make a sun-drenched room museum-grade. And because openness is a physical weave, there's no adjusting it later: the number you order is the number you live with, which is why this is the one spec worth deciding with samples in hand at your own window, at the time of day the sun actually hits it.

Bring the question to a free in-home consultation and we'll hold the fabric card against your glass at 4pm — the honest test no website can run. Solar shades are made to measure here in Coquitlam, in openness factors and colours across the catalogue's 175 fabrics, and picking the right number the first time is the entire game.