Do curtains and blinds block UV rays?
Updated
Cancer Council Australia says window glass typically blocks UVB and some glass reduces UVA. Its advice does not mention curtains or blinds, so for your skin follow its sun safety advice. What curtains and blinds do is cut glare and light, and a lining shields the face fabric from the fading that light, heat and UV all cause.
People ask this for two reasons: to look after their skin, and to look after their furniture and fabrics. The answers differ, so they are kept apart here.
Does window glass already block UV?
Cancer Council Australia answers this in its page "Should I wear sunscreen when indoors?" It says glass typically blocks UVB and some types of glass reduce UVA, and that laminated glass eliminates UVA. It says ultraviolet exposure through windows presents minimal risk of skin damage, and that if you spend a lot of time by a window in direct sunlight you might want to think about sun protection.
That advice is about glass and does not mention curtains or blinds, so don't count on a curtain or blind to protect your skin. For your skin, follow Cancer Council's sun safety advice.
What do curtains and blinds do about the sun?
- Sheer curtains soften glare and still let you see out. They give privacy by day, not at night with the lights on.
- Light filtering roller blinds let soft daylight glow through and hide the room.
- Sunscreen roller blinds are an open mesh that cuts glare and keeps the view out by day. A lower openness figure means a tighter weave, less glare and less view. Sunscreen is the name of a fabric type. It describes glare and view, not protection for your skin.
- Blockout (blackout) curtains and blinds stop light passing through the fabric.
- A lining sits between the face fabric and the window and takes the sun in place of the face fabric.
Which curtain fabric stands up best to the sun?
All fabrics fade gradually over time, and a curtain that has hung in the sun can end up a different shade from new fabric of the same colour. Resene, in its Habitat article on sun damage, says visible light and heat fade furnishings, and that not much UV gets in through window glass. Light, ultraviolet and heat all play a part, along with the conditions in the room.
Resene also says:
- Sun fading affects colours with a lot of red in them the most.
- Acrylic and polyester stand up to sunlight better than many other textiles.
- Lined curtains resist fading better than unlined ones.
Tell your retailer which way the window faces and how much sun it gets. Ask about the fibre and colour of the fabric you like, and whether a lining suits that window. Speedy Blinds makes sheer curtains, linings and sunscreen roller blinds for retailers.
Other ways people ask this
Do sheer curtains block UV rays?
No general UV figure applies to sheer fabric, so for your skin follow Cancer Council's sun safety advice. A sheer does soften glare.
Do linen curtains block UV rays?
No general UV figure applies to linen either, so ask your retailer for the supplier's information on the fabric. Linen, like any fabric, fades gradually in sunlight.
Which curtain fabric is best for sun protection?
For the curtain itself, Resene says acrylic and polyester stand up to sunlight better than many other textiles, and a lining helps. For your skin, follow Cancer Council's advice.
Do sheer curtains reduce glare?
Yes. A sheer softens glare while still letting you see out. How much it helps depends on the room and the window, so look at a sample there.
This answer is general information. For your own windows, your retailer's advice and your order with them come first.