Room Darkening Material For Windows And Your Security

Not only will room darkening materials keep outdoor light from getting in but will also keep indoor light from getting out.

Why might this be important and how does it relate to preparedness?


Keeping indoor light from being visible to the outdoor world might be a concern and a high level consideration for those who are into a higher level of preparedness (SHTF collapse).

The reason is this… When it’s dark outside it becomes very easy to see inside someone’s home when the lights are on. This is obvious right?

You might say that ordinary shades, blinds, and other typical window coverings will prevent those on the outside from seeing in. While it may be true that these window covering materials will prohibit anyone from seeing detail into the inside of a lit home, the issue is that those on the outside will be able to see that there are lights on and that someone or someone’s probably actually in there. The house is ‘live’.

Ordinarily and during ordinary times this is not an issue, and in fact is a deterrent to the ordinary thief in the night who may pass on to another home seeing that it’s lit up and someone’s home.

HOWEVER, for those who are well into preparedness, there is an entirely new set of security considerations when you begin to hypothesize a truly worst-case scenario whereby society has collapsed into social chaos within a world of broken supply chains, grid down, and marauders in the night.

You as a prepared prepper may have the material items to keep on living a life with food, resources, light, and other such conveniences while others may be without. Some or many of those who are without will likely span out while looking for those who “have”.

During this hypothetical time, the location of preppers who have prepared may easily be identifiable by light shimmering through their window at night while most others are in the dark. This will be even more apparent following the first week or two because others will have run out of fresh batteries for their flashlights, fuel for their lanterns and generators, and most other modern conveniences and supplies.

That said, it may be prudent to think of a method to completely darken your windows and to acquire the materials to do so, just in case…

Note: For cost and material savings, rather than coming up with material for all windows, you might consider setting up one or two rooms as your “night rooms”

A few ideas include room darkening material such as black plastic Visqueen, Duvetyne blackout fabric or other such material which can be cut to fit your windows.

Visqueen Plastic Sheeting

Duvetyne Fabric Yard Bolt

Professional Premium Grade Gaffer Tape

Blackout EZ Window Cover, Large

Blackout EZ Window Cover (other sizes)

Room Darkening

Another option is ordinary plywood nailed or screwed to the window frames. Since the hypothetical time we speak of will be one where the aesthetics and cosmetics of one’s home will not be that of keeping up with the Joneses, the appearance won’t matter, right?

There are all sorts of ways to look at the hypothetical situation of a collapsed society and there are all sorts of questions regarding the extent of security measures that we might need to take. The simple aspect of window darkening is one which may help you to blend in and not be seen at night in an environment where everyone else is in the dark…


  1. Some rather expensive options there. Why not use some black 6 mil visqueen?

    1. I was thinking the same. Of course using something heaver and would last longer is not a bad idea but I have the roll of plastic in my shed.

  2. It takes a little time and effort, but I made blackout curtains to fit my windows from heavy fabric found at a thrift store and scavenged lumber. Two dollars total to do one room. It works.

  3. I am really looking forward to suggestions for fabrics or covering.

    I hope there are also some suggestions as to how they can be installed and yet stilled be opened during the day.

    I have been considering pond liner because it comes in a ten foot width and would cover my large south facing windows.

    Thanks. Stay frosty.

    1. Mine are made to fit the frame between the double windows, so theoretically you should be able to open both windows and get a minor draft even through the frames. But they just slip right out. In an SHTF situation you would initially be more concerned about security than open windows, though.

      1. Lauren,
        Problem is that in winter when it is 0 degrees out the sun coming through those big windows heat my house. Also, it would be so depressing to be cooped up in a dark house. Security wise, it would be nice to see who is out there during the day.
        Stay frosty.

        1. @Pieface, The hypothetical notion is to use them at night during a worst-case collapse scenario. Ideally you would let light back in during the day unless it’s too much of a pain to continuously remove them.

          One consideration is to set up one or two rooms with dark window coverings and use those rooms for night-time activities where you may be using indoor light. For those with a basement, maybe that’s the place for such activities at night (block the basement windows if you have them).

      2. Don’t underestimate the need for ventilation.
        We have 24 hours of daylight here in the summer. When we first moved here, the wife put up blackout curtains in the bedroom — couldn’t breathe!

  4. Let’s see Ken posts a article about indoor grow lights now an article about room darkening window material. Hmmm. Ken are you growing those special “HERBS”. Lol. Been hanging out in Cali to long?

    Adapt and Overcome.

  5. If I’m ever forced to “darken ship” I’ll simply duct tape black plastic over the inside of all the windows and place a privacy screen in front of the doors to help block internal light from escaping out. I’ll also tape red cellophane over all my ceiling light fixtures and lamp shades and flash lights, use red globes on the kerosene lanterns (already have several red globes) and use red Christmas bulbs on night lights (already do that) Plus… don’t turn on as many lights as I already do even when they are covered over with red. You can buy packs of large sheets or rolls of red cellophane at Hobby Lobby… at least you used to. Might not be a bad idea to stock up on packs of red cellophane sheets.

    Red lighting does not degrade your night vision like normal white light and is hard, or impossible to detect at distances.

  6. I have thought about this , and glad you posted this article , Ken.

    One idea might be to get a roll of tar roofing paper , it is not messy ,it is cheap and some good duct tape down at hardware store. That should do a good job . And using a red filter over flash lights is good idea from other post .

  7. Good post and a situation that we need to be prepared for when/if the time arrives .
    We have 15 # felt paper,heavy duty black plastic bags and lots of duct tape and lath to fasten stuff to the inside of the window casings with .
    We will also remove any outside light bulbs so that they do not get turned on by accident . A bright light in the middle of darkness can be seen for quite a distance , especially if someone is looking over an area for signs of life .

  8. Thank you for the info. and links Ken.
    We have room darkening pads that double as chalk “boards”.
    They are basically giant table cloths that are lined and used for chalk writing.
    They sell them at Wal Mart and are cheap.
    They can be nailed up to the windows for black out privacy if needed.

    1. To give an idea of the price of the lined black cloths we bought; last Christmas they were 75% off so they cost .98 cents a piece for 60in X 84in!!

  9. I would go with Ken’s idea of just blacking out 1 or 2 secure rooms preferably with a back exit. Stay to that room keep a few diversionary food supplies in the pantry like an old can of cat food and some canned Lima beans. Just in case you are raided. The rest of your main supplies should be properly cached in alternate secrete locations. i.e. burned out buildings, buried in the ground under dead people or animals. In a pit toilet. You can get pretty creative with hiding your supplies.

    If a group of Bad guys are on your door step you will be fighting them on their terms. Better to escape and evade regroup and fight them on your terms when they let their guard down.

  10. Not sure what is best out here in the forested country. Is a dark house more of a target because it looks abandoned or is a well lit house a sign that someone is prepared to defend it to the end?

    1. homebody,
      We have had the same question, we are in a rural ,lightly forested area . Many folks in our area have some type of backup lanterns or candles. We think a dim glow at a window would not attract too much attention , versus many brightly electrical lit windows .We would still practice a lights out “OPSEC” . Hope we never find out .

  11. The military uses blue and red lenses in their old 90 degree goose neck flashlights. They also use green chemical light sticks with an adjustable slide opening container. Please do not use a black light as it will light you up with all the phosphates in detergents. I guess you can get colored light bulbs to cut down your light signature and the colors that can be used to protect your own eyes night vision.

    The bad guy using night vision is a problem.

    I have 6 mil. black visqueen and a stapler

    1. Forgot this.

      I am going to try and use a hot glue gun to fold over the 6 mil. plastic so it makes a hole to slide a curtain rod through it. Save the staples for something else if it works.

  12. If the concern is simply blacking out windows during a SHTF to prevent light from showing outside at night and broadcasting that your house is indeed “live”, there is an old standby that most of you already have…

    aluminum foil.

    Yep, I went there – lol

    Looks “redneck”, and maybe that’s a good thing for SHTF, maybe not. Taped to the window frame and covering the glass, the foil will allow ZERO light penetration and the window can still be opened.

    Not nearly as versatile as making a custom fabric treatment, but in a pinch it will work, and work well. Depending on the fabric, or even the mil thickness of black plastic, some light may still show through. And even the smallest amount of light can act as a beacon. Take a standard black plastic garbage bag, cut it open so it is one layer thick, tape it up over a window, then go outside and look. I did this with a heavy yard debris bag and could still see the light fixture over the kitchen table.

    On a dark night (overcast or no moon), the glowing ember of a cigarette can be easily noticed more than 200 meters away unassisted. Flashlights are visible for much greater distances.

    The old blackout drills of WW2 taught us that even a sliver of light escaping from someone’s window could be seen by enemy bombers flying high overhead. And those were the days BEFORE night vision, FLIR, etc. Imagine how much easier that light will be to see for someone a few hundred yards away on the ground.

    If you need to “blackout” your home in a hurry, remember the aluminum foil will work in a pinch.

    1. I wonder if the aluminum foil would also provide some insulation? If it was summer and you were trying to keep cool, it seems that foil would block the sun. I don’t know if there would be any added heat preservation for winter.

  13. TSHTF, and all heck is breaking lose…. right?
    I have to ask the question, “Why would anyone have ANY lights on at night?” I mean seriously, there is a LOT of light during the ‘day’ to get everything you need finished, even at night the moon/stars is going to give off enough light one can see enough to perform simple task and use that TP. During the dark hours you’re more than likely are doing patrols around the perimeter, sleeping, standing watch, and such, not setting the dinner table and having a first class meal.

    Additionally the human eye becomes very accustom to the dark, and just the slightest amount of ambient light is enough to see with. As some have mentioned red light will keep your ‘night vision’ but if you can see the red light, so can others that could be ‘the bad guys’.

    Now I do understand there may be times when ‘light’ is needed, like stitching up a knife wound or bullet hole, but other than that, keep the lights turned off, you will be able to see the boogie man a lot easier than trying to adjust your eyes after you hear a bump and decide to investigate.

    Is having the ability to ‘black-out’ a room a good idea, sure it is, but one might also remember, you just also blocked off seeing out those same windows for the bad-guy. I like some ideas on having one or two rooms blacked out, BUT remember again if the door to the rest of the house gest kicked in…… what ya going to do because your eyes are not adjusted to the dark?

    Lastly, Ken mentioned “Some or many of those who are without will likely span out while looking for those who “have”.” Will not having blacked out windows be a HUGE flag to others that you might have “stuff” in there they WILL take?


    1. NRP,

      My sentiments exactly. Maybe one central room blacked out for emergencies, preferably where communications gear is located. Otherwise interior lighting should be avoided.

      Having thought about this subject before, I have played with the idea of judicious use of lighting inside the home for bait. Since my plans are for an every night outside posting for perimeter security after dark, an occasional night when everyone sleeps outside in the woods surrounding our home, with a light on inside, would give an opportunity to see what kind of predator might be drawn in. Of course this would require strict light discipline for everyone outside, and the ability to deal with any threat that’s drawn in. This would be for my remote location. Probably not good for a more urban location.

    2. Just a reminder-the further north you go the longer the nights are. Over twelve hours of darkness is hard to live with.

    3. NRP
      Yes, a very low wattage light bulb. We mushrooms do need a little light to grow lol. Besides being in the dark night after night is not good for the mind.

      Dark out curtains, yes I can see them being used. In our area when the power goes out, a small light, even a candle can be made spotted, and which household it is located at.

  14. I was thinking about sheets of plywood painted black on one side. If I could cut them to fit so that they could rest on the sill and still get full light blockage, put some handles on the inside for easy installation/removal… These could double as protection from the elements if a window gets broken. I would love some feedback on this idea…

    1. Good idea Skibum,

      Would add some latch-locks on either side too, sure it wouldn’t stop indefinitely unless one had bars across the windows, but it would at least slow or deter entry….

      Just putting this idea up for thought but thinking it would be wise to purchase materials for improved window security/black out NOW (if you are able) rather than wait…you wouldn’t have to install it right away just have all the pieces ready to go, ya know?

      Peace and Wisdom to all…

      1. Shepherdess, that was exactly my thought, to get the plywood cut, painted,etc soon since that it will be there when (if) needed. I could store it in the shed. The idea began when discussing home repair materials on this site a while back.

    2. @ Skibum

      Plywood cut to fit the window from the inside, with handles to insert and remove it is a great idea, if you don’t have curtains or draperies or if you don’t have a bunch of furniture in front of the window. I was going to do that but decided against it because I have thick floor length drapes on most of my windows and the plywood would only create a serious hazard if I had to escape an emergency like a fire, especially at night. Imagine, if you will, stumbling around in the dark trying to navigate through a bunch of draperies, end tables, dressers, your children and wife while trying to remove a sheet of plywood from your window (even though it has handles and was easy to put in during the day) and the plywood hangs up on a drape or end table and the harder you try to force it the more tangled it gets… your wife and children are screaming and smoke is pouring into the room. That would not be a pleasant experience. If anything, I’d put plywood on the outside with screws large enough to keep it on but small enough to enable you to kick the plywood off in an emergency.

      Personally, I’ll stick with thick black plastic and duct tape or anything other than plywood. Plywood on the inside will create a trap you probably don’t want to be in.

      1. You might consider using polystyrene instead of plywood, for light control only. Use black fabric for whatever faces outside (and an attractive print or color for the inside layer), then sew on some fabric ‘handles’ for the inside. Cut the polystyrene pieces to fit the inside window frame and can be easily removed and replaced with the handles. This would allow you ventilation when desired and extra insulation for the windows when needed (to keep warm and cool, along with minimal heat signature blocking). These would be helpful to have now, and even more so in a shtf situation. I am thinking about the polystyrene sheets that are sold as insulation to go between the studs because they could be sewn in an envelope of material that would allow folding for easier storage during the day.

  15. Lights on in the house for family. Hard to sleep 12 hours a day. Somebody has to be outside on watch and most of us are not going to have enough people to do an adequate job. Trip wire alarms mandatory and easy to rig.
    Red lens on the flashlight? First IV I ever started other than in practice was while holding a flashlight with a red lens in my mouth. Prayed so hard that nobody would shoot the light.

  16. When I built my retirement home, I was already into prepping for a potential societal meltdown and the possibility of life w/o electricity. I had to make a decision on whether to build a fortified home, or one with many windows for ventilation to cope with mid-south summers w/o a/c. I opted for windows (21 in a 1300 sq. ft. home, making it more difficult, but not impossible to black out), with fortified posts in the woods surrounding the home for defensive positions. My hopes and prayers are that I never have to go to this plan of action, but in the words of Cpt. Woodrow Call, “better to have it and not need it than to need it and not have it”.

  17. One thing that’s been touched on is that you don’t want to turn on lights by accident. For most of us, flipping the switch as we go into a room is so ingrained that it’s hard not to do it. I know that I’ve done that when the power was out, without even thinking about it. If you don’t plan to have lights on in rooms, plan on taping over the switches or removing the bulbs. I would think that tape is better, as it’s easy to revert to light usage, you don’t have to store bulbs, and you don’t have to clean dust and bugs out of empty fixtures before putting bulbs back in at some future date.

    1. Light discipline is ingrained into us jarheads, a very simple solution is the breaker box. Make sure your box is well labeled as far as lights, plugs, appliances etc. no need to waste tape or removing bulbs etc. Some of them may need to be left on for various items, but as a whole easier to flip them and avoid accidents. Just insure that refrigerator bulb is removed, and that it is on it’s own circuit or one not on a gfi circuit as well.

      Personally I think in a SHTF situation it’s better to centralize radios, computers etc in an interior room or one that is completely blacked out and leave the remainder of the house to appear normal.

      1. HDB,
        Duh! Yes, of course you’re right. I obviously wasn’t thinking it completely through. Thanks for the reply.

  18. Even if you have one room that is blacked out, you must have a two door entry/exit. Think about an old timey photography or x-ray developing room. You entered one door to a dark hallway, made sure the door was closed behind you, then opened the door to the darkroom. No light enters, no light escapes.

    A little off topic but something that goes along with hiding… The same people who might be looking for light are also listening. I’m more worried about making noise.

    Those same children who are afraid of the dark, or bored in the dark, or people who are injured and/or sick make noise. Not to mention your dog that’s barks a warning.

    We’re planning on no lights except for one room. But, how do we control noise? luv ya’ll, Beach’n

  19. We went with blackout curtains. They have magnetic strips in the edges to join completely. They’re attractive and fit with our decor, so nobody realizes their real purpose.

    Irongate Blackout Curtains

  20. Nothing in Syria that is worth american lives ! War is extremely profitable for the ruling elite and they could care less about American lives .

  21. This past long cold winter I bought several 1 1/2 inch aluminum faced Styrofoam insulation sheets and cut to size for all but south facing windows. The cutting was not perfect but if by adding black plastic several inches oversized, should make good light blocking. The insulation in now stacked in a shower we do not normally use. The shed is full of 3/4 plywood I bought for $5 a sheet as it was not cut square on the 4ft end.

  22. I hit on a window black out option, by total accident. Because of an extremely cold winter this past year…….I was looking for a way to keep heat IN!!! I went to eBay & bought 10 cheap Mylar blankets, for about $10.00.I thumbtacked them in to my bigger windows & the surprising thing was I could see out thru them outside, but from the outside you couldn’t see ANY light inside………I was quite surprised, but learned something, it I kept the old ones & am going to buy a couple more sets as I can afford them.

  23. Up very early this morning and was amazed at the glow coming from the kitchen that should have been pitch dark.
    There was the clock on the stove, the display on the microwave, and the toaster which I forgot to unplug.
    Got me to thinking about all the lights around the house that could be seen if we were trying to be dark, and don’t necessarily involve anyone flipping a switch:
    Little flashers on smoke, radon, and CO2 detectors;
    Laptop, cellphone, and battery chargers;
    Flashlight, cordless vacuum cleaner, and electric power tool chargers;
    Power strips, surge protectors, UPSes;
    Some TVs, computers, game boxes, DVD players;
    Cell phones that light up when jostled and computer screens when there is an incoming message or call;
    The glow from the embers in the wood stove, gas stoves that automatically come on at a set temperature or time;
    Pilot lights;
    Alarm clocks, door bell buttons;
    Alarm systems and motion-activated security lights;
    Even the heating pad has a light on the switch.

    Seems like modern conveniences can also increase the inconvenience of OPSEC.

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