Blockout blinds vs sunscreen blinds: what's the difference?

Blockout blinds stop almost all light passing through the fabric. Sunscreen blinds let some light through but heavily reduce UV and glare while preserving the view out.

A practical rule of thumb:

• Use blockout in: bedrooms, nurseries, media rooms, anywhere you sleep or watch a screen.
• Use sunscreen in: living rooms, kitchens, offices, dining areas: anywhere you want natural light and a view but want to cut UV and glare.
• Use both (day & night dual rollers) in: master bedrooms where you want a view by day and total darkness at night.

Some technical detail:

• Blockout fabric has a coated or laminated back layer (usually acrylic or PVC) that blocks 99-100% of light. The fabric itself is opaque: you can't see through it from either side. Slight light leak is only around the edges, which is solved with side channels or wraparound brackets.
• Sunscreen fabric has a weave with "openness" rated from 1% to 14%. Lower openness blocks more light and heat. Higher openness preserves more view.
  • 1-3% openness: like wearing sunglasses indoors; good privacy by day; some shapes visible at night when lit from inside.
  • 5-7% openness: most common compromise; good view, good UV blocking.
  • 10-14% openness: almost like a screen; best view but the least UV protection.

Important: sunscreen blinds at night reverse. If your interior lights are on and it's dark outside, people walking past can see in. If you live on a busy street or face a footpath, layer with a blockout blind, sheer curtain, or external shutter for night privacy.

For heat blocking specifically, blockout does block more solar heat than sunscreen, but the difference is marginal compared to an external shutter or awning. Heat is best stopped before it reaches the glass.