How to Block Light Leaking From the Top and Sides of Your Curtains

curtains hung up during the day

Any light sleeper knows the struggle falling asleep and staying asleep when there is light coming from outside keeping you awake.

Sure, using heavy curtains or even blackout curtains can make a world of difference in blocking natural light. However, even people that use blackout curtains often face one predicament that prevents them from completely blocking light from outside.

This all too common dilemma is that sunlight seems to always leak out from the top and sides of curtains. Light shining around your curtains, of course, defeats the purpose of using light-blocking curtains for sleep. No matter how good the quality of your curtains is, this problem still can persist.

However, this problem completely treatable. You can block light entirely from seeping around the edges of your curtains by using the three methods below:

Method 1: Applying magnetic tape to your curtains

Method 2: Installing a wrap-around curtain rod 

Method 3: Attaching light blocking window blinds

With these three methods discussed in this post, you can block the light from leaking around the top and sides of your curtains in a cost-effective way.

However, before you use any of these methods yourself, it is important to know if your curtains are set up properly, to begin with…

Common problems with your curtain set up that allow sunlight to leak around the edges

curtains from a side angle

Obviously, if you have abnormally tall, wide, or weirdly shaped windows, your curtains might not be able to completely block out all the sunlight. However, there are a few different reasons why light can shine around your curtains edges that simply that have to do with the set up of your curtains.

Fortunately, a few simple tweaks and adjustments can solve the following problems…

Your curtains are the wrong size

Using the wrong size curtains is the most obvious reason why light might be shining around the edges of your curtains.

You can have the best curtains in the world but if they are simply too small for your windows, you still will have light spilling over.

“How can you fix this?” you might ask.

Well, the only way in which you can fix this problem is by biting the bullet and just buying some new curtains. This time, however, you must be absolutely certain that your new curtains cover the size and shape of your window. Take the time to measure the length and height of the windows you are trying to cover and buy your curtains according to those dimensions.

Your curtains aren’t set up properly

Another common reason why light can shine around the edges of your curtains is that your curtains simply are not installed properly. Your curtain rod could be installed too low or your curtain brackets might not be installed to properly fit the length of your window.

If your curtain rod is installed too close to the top of your window, your curtain might not hang high enough to block out light coming from the top of the window. If your brackets for your rod are too close to the sides of your window, then your curtains might not be able to extend far enough to adequately cover the sides of the window.

“How can you fix this?” you might ask.

The only way you can solve these issues is by reinstalling the curtain brackets and the rod.

To do so, remove the screws holding in the brackets. Next position the bracket first so that your curtains come up at least three inches above the top of your window and at least three inches from the sides of your windows as well, and drill your brackets back in. With your brackets positioned this way, your curtains can completely cover your windows as well as the edges where light seeps through.

Your curtains aren’t close enough to your wall

The last most common dilemma is that your curtains might be hanging too far away from your windows.

When your curtains are hanging far away from the windows, there is ample space for light to seep through around the edges. Curtains that are dangling nearly flush to the wall around the windows are much better at preventing light from coming through.

“How can you fix this?” you might ask.

The only way you can fix this dilemma, as you can imagine, is by hanging the curtain rod closer the wall. If your brackets can be adjusted to bring your curtain rod closer to the wall, then, by all means, make this adjustment. Unfortunately, however, many brackets don’t have this type of adjustability. If this is the case, the following three methods might be your best bet to completely block out natural light…

Three methods for blocking out the light around the edges of your curtains

If your curtains happen to be the right size and your curtain rod is installed in the right spot, yet, you still have sunlight leaking around the edges, these three methods can fix the problem right away.

Fortunately, the following methods are all relatively affordable and don’t take too much time to implement as well.

Method 1: Applying magnetic tape to your curtains

putting magnetic tape on fabric


  • Magnetic tape (I used two rolls)
  • Superglue (optional)

One of the best methods for blocking the light around your curtains is the “magnetic tape” method. This approach is one of the easiest to implement, yet it is by far one of the most effective ways to block unwanted light.

This approach involved lining the sides and the top of your curtains with magnetic tape and then lining the sides and top of the window with the respective other pieces of magnetic tape. In turn, the edges of your curtain will “stick” to the perimeter of the window and will prevent any light from coming into your room.

First, you can start by sticking your magnetic tape to your curtains. Unravel a bit of magnetic tape and stick it to the bottom outer corner on the inside edge of one of your curtains. Slowly unravel your magnetic tape along the side of your curtain as you press the tape against the fabric as you go to make sure that it adheres well. Once you get to the very top of your curtains, snip the tape with a pair of scissors and press the remaining end of the tape into the fabric. Follow the same process along the top of your curtain an inch or more below the curtain rings.

putting magnetic tape on edge of fabric

Follow the same process for your other curtain. 

Quick tip!: Using super glue

Magnetic tape doesn’t adhere as well to some types of curtains. Depending on the type of fabric your curtains are made of, you might find that your magnetic tape peels off pretty easily.

To handle this dilemma, you can superglue your magnetic tape to the edges of your curtains so that your magnetic tape is sure to have strong adhesion to the fabric. To move forward this way, you can follow the same process outlined above, but just line the adhesive side of the magnetic tape with superglue about six inches at a time before you press each segment of the magnetic tape into the curtain. Gluing and pressing the tape into the curtain bit by bit ensures that the glue doesn’t dry out as you carefully lay the magnetic tape onto the edge of the curtain. Be sure to firmly press each glued segment of the tape to the curtain every few inches as you apply the glue to make sure that the tape really adheres to the curtain. Continue this process all the way until the top and then do the same for the tops of the curtains and the side of the other curtain.

The final step of the process is to adhere more magnetic tape to the wall just over an inch away from the window trim.

Determine at which points on the wall around your window trim the edges of your curtain fall. It is recommended that you mark these points on the wall with a pencil since these points along the curtain are where the magnetic strip will need to be stuck to.

Next, you may stick the magnetic tape along these marked off parts of the wall, inch by inch like you applied the magnetic tape to the curtains. 

Once the magnetic tape is in place on your wall, the edges of your curtains should naturally magnetize around the perimeter of your window, thus preventing any light from leaking around the edges of your window.

edges of curtain sticking to wall

There you have it: a 100% blacked-out window. 

Method 2: Installing a wrap around curtain rod

curtain and curtain rod


  • Wrap around curtain rod (and respective wall screws)

Using a wrap around curtain rod or return rod is one of the most natural-looking ways to block off light from around the edges of your curtains. Better yet, no glues or sewing is needed. You simply need to install a return rod properly.

A return rod looks no different than any other curtain rod at first glance. The difference is that a return rod is one continuous rod that curves around at the ends to create a wide U shape. This allows you to draw your curtains into your wall, closing off the sides of your window.

curtain rod with bent ends

The downside of this approach is that although you can effectively block off the sides of your windows, this type of curtain rod doesn’t close off the top of your curtains in addition. However, by installing your curtain rod high enough from the top of your window, you can block most, if not all light from the top of your curtains.  

To install a return rod, first, make sure that you have removed your existing curtain rod. Simply pull out the screws, remove the brackets and the rod. 

Next measure exactly where you would want to mount your new curtain rod. In order to prevent as much light as possible from leaking over the top of your curtains, you will want to plan to mount your return rod as high above the window trim as you can. As long as your curtain rod is placed high enough, you can block out almost all sunlight. 

However, when getting a feel for how high you want your curtain rod to be, make sure that the bottoms of your curtains aren’t hanging too high off the ground. Otherwise, you might end up with the new problem of having light exposure from the bottom of your curtains. 

curtain rod from the ground up

Once you have found the right spot for your curtain rod, be sure to mark the points where you need your wall brackets to be. At these marks, you can drill the pilot holes, and then position the brackets over these pilot holes before drilling in the screws for the brackets. When positioning the brackets make sure that the corresponding rod will be perfectly level. Once everything is lined up, drill in your curtain brackets. 

Once your rod is in place, you can then wrap your curtains all the way across your window and along the sides of your window trim as well.

hanging curtains

Voila! You have now completely blacked out your windows. 

Method 3: Attaching light blocking window blinds

spare window blinds


  • Spare window blinds
  • Superglue or 3M Command Strips

Blocking out sunlight around the edges of your curtains this way involves using individual blinds that would typically hang in front of your window, as light-blocking barriers between the curtain and your window trim.

If you don’t have any spare window blinds hanging around, you can always order a set of replacement blinds for pretty cheap.

First, take one of your blinds and line it up flush along the outer edge of the side of your window trim so that the blind is protruding out from the wall. If your blinds are too tall for your window, mark the spots on the blind where the window ends and then cut the blind at those markings so that the blind fits the length of the window. Do the same for another blind to fit the other side of the window trim and then another for the top of the window trim.

blind pressed up against trim

From here you need to adhere the first window blind to the side of the window trim.

To do so, you can superglue the blind to the edge of the window trim. Of course, this method is more of a permanent solution since peeling the blind off once it has been glued on can damage the paint of the trim. Alternatively, you may use 3M Command strips (essentially tape that doesn’t peel paint off the wall) which you can remove without worrying about damaging your window frame. 

To use superglue, simply apply the super glue to the edge of the blind about six inches at a time. After applying the glue in these segments, press the edge of the blind up against the side of the window trim. Press the blind into the trim firmly to make sure that it really sticks. Gluing your blind to your window trim bit by bit this way will ensure that the glue won’t dry out since you will be applying it to the trim right away. In addition, adhering the blind to the trim carefully in sections will help you make sure that you don’t glue in the blind crooked or out of place.

To use 3M command strips, simply adhere one side of the command strip to the very top corner of the blind and the other side to the very top edge of the window trim. Follow the same steps for the very bottom of the blind. Using 3M Command strips this way is great because you can easily remove them without peeling off paint if you want to take off the blind. The only downside is that 3M Command strips aren’t as strongly adhesive as super glue. 

Whether you use superglue or command strips for the first window blind, follow the same process for the other side of your window and then to the top of your window as well.

curtain pulled over blind

Once finished, these blind barriers should protrude far enough out of the wall to prevent light from leaking out around the edges of your curtains.

Final thoughts

In determining which of these three methods you should use for your light-blocking needs, there are a few points to consider.

Keep in mind that some of these methods may work better than others depending on what type of curtains you have, how they are positioned and what type of windows you have. It is up to you to determine what method might work best for your window.

Regardless of which method you choose to move forward with, plan carefully. 

For a complete list of the best methods for blacking out your entire room, you can check out this guide here!