Solar Screen Openness: 1% vs 3% vs 5% vs 10%
Openness is the share of the weave that is open air: 1% gives the most heat and glare control, 3% is the South Florida default, 5% opens the view, 10% suits shaded glass. In charcoal E Screen, solar transmittance climbs from 3% at 1% to 12% at 10%. Exotic Shades & Draperies shows every openness in Fort Lauderdale and Miami Beach.
Smaller number, more protection, less view
Solar screen fabric is a woven mesh, and the openness factor is simply how much of it is hole. A 1% weave is nearly solid: it stops the most heat and glare and gives the most privacy by day, but the view through it is dim. A 10% weave is airy: you see the water clearly and the room stays bright, and more sun comes through with it. 3% and 5% sit between, which is why almost every South Florida project lands on one of them.
Colour matters as much as openness. A dark weave (charcoal, black, bronze) absorbs energy and gives the clearest view-through; a light weave (white, linen, pearl) reflects energy back out and glows brighter inside but reads more like frosted glass. The table below shows both effects with Lutron's published numbers for Mermet E Screen, the fabric we install most.
E Screen by openness and colour
| Openness | Charcoal/Grey (dark) | Pearl/Grey (mid) | White/White (light) | Across all Lutron solar screens |
|---|---|---|---|---|
| 1% | Tv 2% · Ts 3% · view 25% | Tv 3% · Ts 5% · view 14% | Tv 11% · Ts 14% · view 1% | 107 colourways in 12 weaves; visible transmittance 0 to 18% |
| 3% | Tv 5% · Ts 5% · view 42% | Tv 8% · Ts 10% · view 27% | Tv 13% · Ts 16% · view 17% | 128 colourways in 16 weaves; visible transmittance 2 to 19% |
| 5% | Tv 7% · Ts 7% · view 56% | Tv 10% · Ts 12% · view 42% | Tv 17% · Ts 20% · view 28% | 95 colourways in 13 weaves; visible transmittance 3 to 22% |
| 10% | Tv 11% · Ts 12% · view 81% | Tv 14% · Ts 16% · view 68% | Tv 22% · Ts 25% · view 50% | 42 colourways in 5 weaves; visible transmittance 11 to 32% |
Tv = visible light transmittance, Ts = total solar energy transmittance, view = Lutron's view-through rating, all as published by Lutron for Mermet E Screen (36% fiberglass, 64% vinyl, usable width 120 in, NFPA 701 rated). The right-hand column summarises every 1%, 3%, 5% and 10% solar screen in the Lutron library (Basketweave, T Screen, M Screen, Sheerweave 4900, SheerLite, Aura and others).
What the numbers mean in a room
What we specify in South Florida
West and south glass, ocean or bay
3% in a dark or mid weave. It is the fabric on most of our oceanfront work: glare drops, the view survives, and the room does not go dim. Go to 1% when the afternoon sun is brutal and the view is secondary.
East glass, morning sun
3% or 5%. Morning light is lower and kinder; 5% keeps the room bright and the horizon sharp.
North glass, shaded terraces, covered lanais
5% or 10%. Little direct sun, so openness buys light and view without a heat penalty.
Home offices and TV walls
1% or 3% in charcoal. Screen glare is the enemy; a dark, tight weave kills it while you still see the garden.
Bedrooms
Any openness for the day layer, plus a blackout. Our dual and zebra shades and blackout rollers in side channels cover the night.
Not sure?
We bring the memo samples to the window at the hour that bothers you and let you look through each one. Or upload a photo to the visualizer and try the colourways on your own glass.
Where these figures come from
- Lutron fabric specifications (lutronfabrics.com), values as published for each colourway, retrieved September 2026 - openness, Tv, Ts, Rs, view rating, composition, width and fire rating for E Screen and the other solar screen weaves quoted.
- Exposure recommendations are Exotic Shades & Draperies' own practice from installations across Miami-Dade, Broward and Palm Beach counties.
Frequently asked
What openness is best for a Florida living room?
3% in a dark or mid colour for most west, south and waterfront glass; it controls glare and heat while keeping the view. East-facing rooms can go to 5%, and shaded or north glass to 5% or 10%.
Does 1% openness block more heat than 3%?
Yes. In Mermet E Screen charcoal, total solar transmittance is 3% at 1% and 5% at 3%; at 5% it is 7% and at 10% 12%. The difference between 1% and 3% is smaller than the difference in view, which is why 3% is the usual pick.
Which colour keeps the view best?
Dark weaves. Lutron rates E Screen charcoal 5% at 56% view-through against 28% for white at the same openness. Light colours reflect more heat and brighten the room but look more like frosted glass.
Can people see in at night?
Yes, through any solar screen, once the interior lights are on. For bedrooms and street-facing rooms we add a blackout layer: a dual roller, a zebra shade, or draperies.
Is 10% openness ever the right choice?
On north glass, covered terraces and rooms with little direct sun, 10% keeps the room bright and the view almost unobstructed. On a west-facing Miami window it would be underpowered.
Do you carry all four openness factors?
Yes. The Lutron fabric library we carry lists 372 solar-screen colourways at 1%, 3%, 5% and 10%, plus 0.5% and 2% specials; every one can be ordered as a memo sample and seen at either showroom.
Weigh it in your own light
Bring a floor plan or a window list, or book the free in-home consultation - we bring the samples, measure, and put a written number on each option.