Please see the pictures below. To reduce the light levels to aid in sleeping, how can I block sunlight and the midnight sun for the duration of the midnight sun e.g. 6 months? How can I blacken a bed-room? I must still access the balcony, so the balcony door mustn't be hindered.

I'm shunning any adhesive, because tape can damage surfaces and rip off paint. Let's treat removing the vertical blinds as a last resort.

Top to bottom. https://www.tripadvisor.com/ShowUserReviews-g155019-d8027415-r444957857-Natural_Light_and_Sweeping_City_Views_in_Downtown_Toronto-Toronto_Ontario.html. https://www.houzz.in/photos/vertical-blinds-in-a-downtown-condo-phvw-vp~45007999. https://windowcoveringstoronto.ca/blinds-toronto/condo-blinds/. https://dansblinds.ca/how-to-choose-window-coverings/.

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    Do you want to cover the windows or just the glass? I do not understand 'conceal' the windows. Must the solution to your question be temporary or semi-permanent? Do you want opaque or translucent?
    – Stan
    Commented Jul 7, 2020 at 4:54

9 Answers 9


If you're looking for something lifehacky for this and you're not too bothered about the end result aesthetic you could lifehack upgrade the blinds. I make this recommendation instead of suggesting window films, sleep masks etc because you didn't state this was just for sleeping, or that you want it dark all the time. By having the blinds better able to regulate the light you can hopefully adjust the room brightness on demand, keep a sensible circadian rhythm, mimic the natural day/night cycle, have darker evening hours but still be able to move around the room as normal etc. To this end I think you'll need a solution that doesn't involve wearing masks, making the windows opaque etc

I suggest that you could:

  • Obtain a roll of paper, such as wallpaper with a reasonable pattern, or colored paper like kids use in arts class
  • Measure the width and length of a blind slat
  • Cut a strip of paper the length of the blind slat and twice its width plus 20mm
  • Fold the paper in half along the length so it's like a very tall book (with two pages)
  • Fit it onto the blind slat, from the window side ("spine" towards window), so that the "pages" of the fold are either side of the slat
  • Use a stapler to staple the protruding ~10mm bits of paper together, putting the staple through the "pages" but not the blinds

You could alternatively consider using something like bobby pins/hair grips or paper clips to hold the paper in place - you might not need the protruding 20mm in this case. Tape may also work if you leave a small protrusion but it does tend to degrade in sunlight

The aim is to turn your blinds into blackout blinds by making them more opaque with a thin and cheap material. I picked wallpaper because it's probably quite easy to obtain something good looking and opaque

Fitting the paper so the staples are on the window side will be more awkward but give a better look

If this works well for you physiologically/psychologically you could consider replacing the blind slats with a blackout material - more expensive but worth it if you know it will work

Note: the easiest way to make a good straight cut is with craft knife (x-acto knife, Stanley knife or whatever your country calls it) or razor blade, run down the edge of a long straight bar/ruler with the paper resting on a temporary surface that can be discarded after it has been ruined by the repeated cuts with the knife (an opened out large cardboard box perhaps)


Assuming you have difficulties sleeping when the sun shines even at night, consider using a sleep mask instead of blocking all of those windows. I often sleep with a mask in summer and a well-fitted one stays in place all night long, so you can put it on in the evening and still be protected in the morning.

Unfortunately there are vast differences in quality between different masks.

  • Make sure it fits you very well around the nose and cheeks. That's where you'll be most bothered by light.
  • Make sure the material is thick enough to block light. Black fabric is the safest bet, but even a very thin black mask will let some light through.
  • Make sure it's comfortable enough to sleep with. Some masks are quite bulky and might hurt you when sleeping on your side.
  • Make sure the strap(s) is/are adjustable to your individual size. If you can handle a needle and thread, you can shorten the strap with a few stitches.

I ended up sewing my own sleep mask, which is a very easy beginners project and lets me adjust the mask to my preferences perfectly.


e.g. 6 months

Well, 6 months is not 3 days. What you need is not a life hack, but a proper solution. Replace all the fancy blinds with proper blinds.


  • use the fancy blinds during the dark 6 months, and the proper blinds during the light 6 months;
  • have both blinds installed; use them as you see fit. E.g.: if you have a night party during the light nights, you can use the fancy blinds.

For this, you need top contact a business that deals with the stuff - they have the mechanisms, as well the opaque material for you.


My hack is to buy or make a light-reducing box around the bed instead of trying to mask the windows.

Following the idea of this privacy indoor bed tent, which might not exclude enough light, you could make your own light-proof box around the bed.

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Build a timber framework held together with bolts and wing nuts. Staple same thick fabric to it, and make a ceiling too. Don't forget to allow for some ventilation.

Six months later prise out the staples and dismantle the frame, fold the fabric and store away for next time.

Image from Amazon

  • 1
    Make sure to provide enough ventilation if you do this. Fabric thick enough to block out the sun doesn't ventilate well so you get CO2 buildup.
    – Hobbes
    Commented Jul 8, 2020 at 11:43

Install blackout curtains. Hotels use them a lot for the comfort of their guests who may want to sleep during the day. You can order them online. And, curtain rods are not that hard to install. Curtain rods come with their own hardware. You will just need a screwdriver.


Have you heard of static cling?

Some kinds of plastic film will stick to glass without adhesive using only static electricity. When you do not want the effect, you peel it off and roll it up for storage. Unroll it for reuse. Easy on, easy off.

Light Block Window Film

You would be most interested in Light Block Window Film. There are all different kinds of window films—UV blocking films, IR blocking films, and various kinds of patterns and opacities up to total block out. You might even be interested in gradation from clear to opaque.

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Solid white can also block light from the outside and has the added benefit of a bright interior with normal room illumination if you don't want to open blocked windows.

The stuff can be found in major hardware stores and home renovation centres.

Good luck


Vertical blinds have 2 problems:

  1. they are not entirely opaque,
  2. there's a gap between the window and the blinds, which means quite a lot of light gets in.

You can get cassette blackout blinds (random example) which solve both problems. The cassette is fitted in the window frame to ensure there's no gap for light to get through, and the material is opaque.

Because they're installed in the window frame, they won't interfere with the existing blinds.

But it's difficult to find a flexible material that's opaque enough to block out the sun completely - I've got blackout blinds and I can still tell when the sun shines directly on the window. The amount of light getting in is very small - the difference between pitch black and being able to tell the room has a window. The ultimate solution is metal roller shutters on the outside of the window.


You may consider electrotropic foils or electrochromic glass. Both share that their transparency is altered by applying a low voltage current.

  • Using an electrotropic foil requires that this special foil is attached, similar to scotch / adhesive foil to already existing plane glass surfaces. An elder demonstration (prices reflecting the UK back in 2017) is shown here, a larger application / home improvement here.

  • You may opt for electrochromic glasses like SageGlass by St. Gobain. Here, the material responsive to the electric current resides within the glass (actually, multiple layers [architecture]). Because it is glass, some variation of colour may be added, too. Of course they made commercial-like presentations like this one, but are not the only on the market (e.g., example, example). In this case, you may get rid of blinds altogether. An other brand name is SwitchGlass.


Depending on the type you buy, many blackout curtains and blinds will also include sufficient insulation to help with noise reduction and temperature control.

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