Blockout fabric stops light getting through. Sunscreen cuts glare and heat while you can still see out, which is why plenty of Sydney houses end up with both, sometimes on the same window.
What blockout fabric is actually doing
Blockout is a woven polyester with a coating on the back, usually two or three passes of acrylic or a PVC layer. Light does not pass through the fabric at all. Most of the blockout we roll sits somewhere around 250 to 340 gsm, which is why it hangs heavier and needs a bigger tube than a sunscreen of the same size.
The fabric blocks the light. The install decides whether the room actually goes dark, and that is a separate question worth getting right.
Where sunscreen earns its keep
Sunscreen is a mesh. Threads of PVC coated polyester or fibreglass woven with tiny gaps between them, so it knocks back the sun and the glare without closing the window off. Sit inside on a bright day and you can see the garden clearly. Stand outside and the glass looks dark.
That flips at night. Turn the lights on inside and someone on the footpath can see in, so sunscreen on its own is not a privacy fabric for a bedroom or a street facing front room.
Openness factor, in plain terms
Openness factor is the share of the fabric that is hole rather than thread. The common ones are 1%, 3%, 5% and 10%.
- 1% and 3% block the most sun and give the best daytime privacy. The view out is softer and a little hazier.
- 5% is the middle ground, and the one we fit most often in living areas facing north or east.
- 10% keeps the view sharpest and lets through noticeably more glare, so it suits a shaded window or a room where the outlook is the whole point of the house.
Colour matters as much as the number. A charcoal mesh controls glare better than a white one at the same openness, and it gives a clearer view out. A white or pearl back bounces more heat off the glass and looks brighter from the street, which is why a lot of fabrics are made with a light back and a dark face.
West facing glass is its own problem
West facing windows in Sydney take a beating from about two in the afternoon through summer. On those we usually go tighter, 3% or even 1%, in a darker mesh.
Blockout will stop that sun completely, but you lose the room while it is down. A sunscreen keeps the space usable and takes the sting out of the glare, which is normally what people actually want in a living room at four o clock.
Heat is worth thinking about separately from light. A tight sunscreen with a pale backing reflects a fair part of the heat before it reaches the glass, which takes some load off an air conditioner working through a January afternoon.
Light gaps are the part people notice
A blockout blind fitted inside the reveal still leaves roughly 5mm of gap each side, because the tube has to spin in its brackets. In a bedroom that reads as two bright lines on the wall at six in the morning in December.
Two ways around it. Face fix the blind and run the fabric 150mm past the glass either side, or fit a cassette or a pelmet so the top and sides are closed in. If a room has to be genuinely dark, say so at the measure and we will set it up for that from the start.
How we normally split it, room by room
Bedrooms get blockout. Kids rooms especially, because early sun makes a real difference to how long a toddler stays asleep. Media rooms are the same.
Living areas, kitchens and home offices are usually sunscreen. You keep the view and the daylight, the glare comes off the television and the laptop screen, and the floorboards and furniture get some protection from fading.
Rooms that have to do both jobs, which is most open plan living now, are where a double roller makes sense. Two blinds on one bracket, sunscreen through the day and blockout at night, each on its own chain or motor.
If you are not sure which way to go on a particular window, that is what the free measure and quote is for. We will bring both fabrics out, hold them up against your glass at the time of day that bothers you, and you can see the difference yourself. Start with the blockout roller blind range, compare it with sunscreen fabrics and openness factors, or look at how a double roller blind runs both on one bracket.
Common questions
Does a blockout roller blind make a room completely dark?
The fabric blocks all the light, but the install decides the result. Fitted inside a reveal you still get about 5mm of gap each side. Face fix the blind 150mm past the glass, or add a cassette, and the room goes genuinely dark.
Can people see through sunscreen blinds at night?
From outside, yes, once your lights are on. Sunscreen mesh works on the difference in brightness between the two sides, so it only gives you privacy in daylight. For night privacy you want blockout, or a blockout paired with sunscreen on a double bracket.
Which openness factor should I choose?
Around 5% suits most living areas. Drop to 3% or 1% on west facing glass or anywhere the afternoon glare is bad, and go to 10% where the view matters more than the sun. A charcoal mesh controls glare better than white at the same openness.