Blackout Curtains or Blackout Blinds for a Bedroom in Malaysia?
For a bedroom in Malaysia, blackout curtains and blackout blinds can both make the room dark: the fabric blocks light either way, so the edges decide. A blackout roller blind fitted inside the window frame leaves thin light gaps at its sides; side channels reduce them. A blackout curtain leaks light over the top and in the middle unless it is hung high, wide and overlapping. For the darkest room, use both.
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Key takeaways
- A blackout roller blind fitted inside a window frame has light gaps at its edges, because a blind fitted tight would rub on the frame, Hunter Douglas explains. Side channels reduce them.
- In a Northwestern University study, sleeping one night in 100 lux of moderate room light raised night-time heart rate and next-morning insulin resistance, compared with sleep in under 3 lux.
- In a Japanese study of 863 older adults, bedrooms averaging 5 lux or more at night were linked with a higher risk of depressive symptoms (an association, not proof of cause).
- Silent Gliss dim-out blind systems, which Promolink supplies, hold the fabric's edges in side channels with a zip profile for room darkening.
Which blocks more light in a bedroom: blackout curtains or blackout blinds?
Neither wins on fabric alone: a true blackout fabric stops light passing through it whether it hangs as a curtain or rolls up as a blind. The difference is how much light gets round the edges. A curtain can be made wider and taller than the window, so it overlaps the wall. A blind fitted inside the window frame cannot.
Check the label, too. The German textile maker Ibena describes dim-out fabrics as opaque, meaning objects or persons behind them are not visible
, and blackout fabrics as usually multiple-layered, light-tight
fabrics with a special coating (Ibena). Promolink's Silent Gliss roller blinds come in fabrics from translucent to blackout, so ask for blackout for a bedroom.
Where does light get in around blackout blinds and curtains?
Light gets in around a blackout blind or curtain through the gaps at its edges, not through the fabric. Hunter Douglas, the window-covering maker, says these light gaps are common to all blinds or shades that are mounted on the inside of window frames
, because if the blinds or shades were mounted tightly against the frame, their edges would rub on it
(Hunter Douglas).
- A roller blind leaks at both sides, over the roller if it has no headbox, and under the bottom bar if it stops short of the sill.
- A curtain leaks over the track if the track sits below the ceiling, round the ends if it stops at the window frame, and in the middle where the two halves meet.
In a Malaysian city, night light comes through those gaps as well as morning sun. Researchers at Universiti Teknologi MARA (UiTM) measured the night sky over Kuala Lumpur's city centre as 5 times brighter than over Teluk Kemang, a suburban site near Port Dickson, from August to December 2015 (Faid et al., 2016).
How dark should a bedroom be for good sleep?
A bedroom should be as dark as you can make it, because even moderate room light during sleep changes how the body works overnight. The US National Institute for Occupational Safety and Health (NIOSH) advises room-darkening shades or heavy, lined draperies; pin drapes closed
, and to block any light entering the room
(NIOSH).
In a 2022 Northwestern University study of 20 young adults, one night of sleep in moderate light (100 lux) increased night-time heart rate and next-morning insulin resistance, compared with sleep in under 3 lux (Mason et al., PNAS 2022).
"It's important for people to avoid or minimize the amount of light exposure during sleep."
Dr Phyllis Zee, chief of sleep medicine at Northwestern University Feinberg School of Medicine, Northwestern Now, March 2022
Among 863 older adults in Nara, Japan, those whose bedrooms averaged 5 lux or more at night, a twentieth of that moderate light, had a higher risk of depressive symptoms over about two years (Obayashi et al., 2018). That is an association, not proof of cause, and none of these studies tested curtains or blinds. Dr Zee's quick test: If you're able to see things really well, it's probably too light.
Blackout curtains vs blackout blinds: how do they compare?
Blackout curtains suit wide windows and a soft look; blackout blinds suit recessed windows and a flat, tidy look. The table below sets a blackout curtain, a plain blackout roller blind and a blind in side channels or a full dim-out system side by side: light at the edges, the best window, space and look, cords, and what Promolink offers.
| What matters | Blackout curtain | Blackout roller blind, no side channels | Blackout blind in side channels, or a dim-out system |
|---|---|---|---|
| Light at the edges | Little, if hung from the ceiling, past the frame and overlapping in the middle | Thin gaps at both sides when fitted inside the frame | Side gaps narrowed by the channels |
| Best window | Wide windows, full-height glass, sliding doors to a balcony | Small and medium windows | Recessed windows where you want the darkest blind |
| Space and look | Soft folds; needs wall space beside the window when open | Flat and minimal, in or over the frame | Flat, with slim channels at the sides |
| Cords | None on a hand-drawn or motorised track | Chain, or cordless: spring, battery or electric | Chain or electric; Silent Gliss chain models use a safety retainer |
| At Promolink | Blackout curtains made to measure | Roller blinds in fabrics from translucent to blackout | Roller Blind Blackout with Side Guide; Silent Gliss Dim-out Blind Systems |
When are blackout curtains the better choice for a bedroom?
Blackout curtains are the better choice for a bedroom with a wide window, full-height glass or a sliding door to the balcony, where one blind would be very large. A curtain can hang from the ceiling and run past the window on both sides, covering the gaps a blind leaves.
How you hang it decides how dark the room gets:
- Fix the track at or close to the ceiling, so light cannot spill over the top.
- Run it well past the window frame at both ends, with returns: the curtain wraps round the track's ends to meet the wall.
- Take it down to the floor, so no light shows underneath.
- Make the two halves overlap where they meet. NIOSH's advice to pin drapes closed is about the same gap.
- Put the light side towards the glass to reflect the sun. Our guide on keeping a hot room cool with curtains and blinds covers the heat side.
Promolink makes blackout curtains to measure. Promolink customer Jason Liaw wrote in a review on Promolink's website: Very happy with my new blackout curtains. Especially since my living room is facing the sunlight.
When is a blackout blind the better choice for a bedroom?
A blackout blind is the better choice when the bedroom window sits in a recess, furniture stands close to the glass, or you want a flat, tidy look. A plain roller blind leaves thin light gaps at its sides, so for a darker room choose one that runs in side guide channels, or a complete dim-out system with a headbox, side channels and a bottom bar.
The blind maker Luxaflex says side channels are a clever way to boost the room darkening performance of blinds by reducing light gaps at the edges
(Luxaflex). Promolink offers two blinds built this way:
- Roller Blind Blackout with Side Guide: a blackout roller blind whose edges run in side guide channels.
- Silent Gliss Dim-out Blind Systems:
Total room darkening
for rooms including bedrooms, fitted inside or outside the recess, electric or chain.
Silent Gliss's technical catalogue for these systems, linked from Promolink's page, lists an aluminium headbox, a 40 mm side channel and a bottom bar, with the fabric edges retained by two component zip profile
; the chain-operated SG 4740 takes blinds up to 3 m wide by 3 m drop (Silent Gliss catalogue).
Where channels will not fit, mount the blind outside the recess. Hunter Douglas notes it will fully overlap the window
, though you might still get a little glow
.
Should you use a blackout blind and blackout curtains together?
Yes, a blackout blind in the window recess with blackout curtains over it gives the darkest bedroom, because each covers the gaps the other leaves. The curtains hide the blind's side gaps, and the blind stops the light that gets past the curtains' edges.
A double track can also carry a sheer for daytime privacy and a blackout curtain for night. Promolink's Roman blinds come as a two-layer system, sheer for day and Roman blind for night, but its own page says Roman blinds do not offer light filtration that is as strong as other blind systems
. For a dark bedroom, pair one with blackout curtains.
Which blackout option is safest for a child's bedroom?
In a child's bedroom, the safest blackout option has no loose cord or chain, and the cot or bed stands away from the window. The US Consumer Product Safety Commission says cordless window coverings are the only option to eliminate the strangulation hazard
, and advises: Move all cribs, beds, furniture and toys away from windows and window covering cords, preferably to another wall
(CPSC).
Silent Gliss's dim-out catalogue says its chain-operated dim-out blinds comply with the child safety standard EN 13120, with a chain safety retainer at least 150 cm above the floor. A motorised blind or curtain has no pull cord; see our guide on whether motorised curtains are worth it in Malaysia.
Where can you get blackout curtains and blinds in Kuala Lumpur and Selangor?
Promolink Actions makes blackout curtains and blinds to measure, with an office in Petaling Jaya and a showroom in Setapak, Kuala Lumpur. Promolink has made curtains since 1998, describes itself as the sole gateway to Silent Gliss in Malaysia, and sews its curtains in-house. It offers free consultation, measurement and installation, with warranty and after-sales care.
Light gaps are won or lost at measuring. Read the Promolink FAQ, browse more curtain and blind guides, or contact the team.
Frequently asked questions
Do blackout blinds let light in at the sides?
Usually, yes, if the blind is fitted inside the window frame. A roller blind needs a little clearance at each side so it can roll without rubbing on the frame, and light comes through that gap. Side guide channels, or fitting the blind outside the frame so it overlaps the wall, reduce it. A blackout curtain over the blind covers what is left.
Is dim-out the same as blackout?
Not quite. As fabrics, dim-out is opaque, so you cannot see through it, while blackout fabric is light-tight, usually multi-layered and coated, says the textile maker Ibena. Silent Gliss also uses the name for complete dim-out blind systems with a headbox and zipped side channels, which Promolink describes as "Total room darkening". Ask which one you are being offered.
Can I put blackout curtains over a blackout blind?
Yes, and it is the darkest set-up for a bedroom. Fit the blind in the window recess and hang the curtains on a track above and beyond it. The curtains cover the blind's side gaps, and the blind stops the light that gets past the curtains' edges. Make sure the curtain track is high and wide enough to clear the blind.
How dark should a bedroom be for sleep?
As dark as you can make it. In a Northwestern University study, one night of sleep in 100 lux of moderate room light raised night-time heart rate and next-morning insulin resistance, compared with sleep in under 3 lux. The study's senior author, sleep researcher Dr Phyllis Zee, suggests a simple test: if you can see things really well, it is probably too light.
Are blackout blinds safe in a bedroom for young children?
They can be, if there is no loose cord or chain within reach. The US Consumer Product Safety Commission says cordless window coverings are the only option to eliminate the strangulation hazard, and advises moving cribs and beds away from windows and cords. Silent Gliss says its chain-operated dim-out blinds comply with the child safety standard EN 13120 and use a chain safety retainer.
Ask which blackout option suits your bedroom window
WhatsApp Promolink a photo of the bedroom window with its rough width and height, and arrange a free consultation and measurement.
WhatsApp usCall 012-292 5582Sources
- Hunter Douglas, Blocking Light from the Sides of Blinds or Shades, November 2021. https://www.hunterdouglas.com/stories/buyers-guides/window-treatments-light-gaps
- Ibena Textilwerke (DPI-TEX), Dimming, obscuring, darkening. https://dpi-tex.ibena.de/en/dimming-obscouring-darkening.html
- Faid et al. (Universiti Teknologi MARA), Monitoring the Level of Light Pollution ... in Selected Areas in Malaysia Using Sky Quality Meter, Journal of Industrial Engineering and Management Science, 2016. https://www.riverpublishers.com/journal/journal_articles/RP_Journal_2446-1822_20161007.pdf
- US National Institute for Occupational Safety and Health (NIOSH), Creating a Good Sleep Environment (CDC archive). https://archive.cdc.gov/www_cdc_gov/niosh/emres/longhourstraining/environment.html
- Mason et al., Light exposure during sleep impairs cardiometabolic function, PNAS, 2022. https://pmc.ncbi.nlm.nih.gov/articles/PMC8944904/
- Northwestern Now, Close the blinds during sleep to protect your health, 14 March 2022. https://news.northwestern.edu/stories/2022/03/close-the-blinds-during-sleep-to-protect-your-health
- Obayashi, Saeki and Kurumatani, Bedroom Light Exposure at Night and the Incidence of Depressive Symptoms: A Longitudinal Study of the HEIJO-KYO Cohort, American Journal of Epidemiology, 2018. https://academic.oup.com/aje/article/187/3/427/4056592
- Luxaflex, Blackout blinds. https://www.luxaflex.co.uk/products/blackout-blinds/
- Silent Gliss, Dim-out Blind Systems technical catalogue (06/2026), as linked from Promolink's Dim-out Blind Systems page. https://www.promolink.com.my/images/uploads/category/70/pdf/SGGB_DO_EN-GB.pdf
- US Consumer Product Safety Commission, Window Covering Safety Education Center. https://cpsc.gov/Safety-Education/Safety-Education-Centers/Window-Covering
- Promolink, Silent Gliss Roller Blind Systems. https://www.promolink.com.my/products/roller-blind-systems-1/
- Promolink, Dim-out Blind Systems. https://www.promolink.com.my/products/dim-out-blind-systems/
- Promolink, Roman Blinds. https://www.promolink.com.my/products/roman-blinds/
- Promolink, customer reviews on the home page. https://www.promolink.com.my/