How to Blackout Oddly Shaped Windows

methods for darkening strangely shaped winodows

Blacking out standard size windows is often quite easy. In most cases, all you need to do is throw up some blackout curtains and voila, you now have quickly and effectively blacked out your curtains.

However, not all windows are built the same. Whether you live in an old colonial house, a uniquely designed modern home or another living situation where the windows simply have unconventional shapes, blacking out your windows might not be so straightforward.

Often times when you have windows that are unusually wide, tall, or oddly shaped, you have to get a bit more creative with how you black them out.

Fortunately, there are two excellent ways in which you can quickly and easily blackout oddly shaped windows by using…

  • Custom roller blackout shades
  • Specially shaped blackout window film

These two solutions are both excellent ways to block light from oddly shaped windows, however, each of these methods is better suited for specific window shapes as you will soon find out. 

Using blackout cellular shades for unusually wide or tall windows

cellular shades and a window

Image source: AnemoneProjectors on

Blackout cellular shades or roller shades are excellent solutions for wacky shaped that are particularly wide or tall in shape.

Often times these cellular shades sizes are extremely customizable in terms of shape and size. Companies like Arlo Blinds, for instance, allow you to choose cellular shades starting at 16 inches in width to 72 inches in width, and various lengths in between with incremental one-inch differences. In term of height, these cellular shades can all stretch out to 72 inches at most which is taller than most windows.

In turn, because cellular shades such as these are so customizable, they are excellent for the most outlandishly wide and tall windows that you can find.

However, the main limitation of cellular shades is that they are only designed to fit rectangularly shaped windows. The windows can be six feet wide or just one and a half feet wide, but they must be rectangularly shaped to accommodate the cellular shades.

When determining the dimensions of the cellular shades you wish to order, being careful in how you measure your window is critical especially if your goal is to completely block out all light from your window. Blinds too short in width will cause light to shine around the edges of the blinds. Blinds too wide in length will fit lopsided and possibly crinkled within your window casing.

When measuring your windows, use a tape measurer from the inner casing on one side to the inner casing on the other side. Make sure that you are measuring completely level. You can use the top casing of the window for reference to make sure that you aren’t measuring crookedly.

You can then order blinds of the same length across as your window casings.

DO NOT measure from sash to sash. If you order blinds that fit the length between your sashes, you will likely end up with blinds too short in length that allow for light to leak around the sides. This, of course, defeats the purpose of blackout blinds.

Using blackout film for unusually shaped windows

blackout film and weird looking window

Most windows have rectangular shapes. However, there are many other windows that do not fit this standard shape at all. Whether you are working with circle top designs, hexagon windows or any other oddly shaped windows, blackout cellular shades typically won’t fit these unique designs.

Enter blackout film.

Blackout film is simply flexible lining that you can stick to your window and then peel right off when you don’t want to use it anymore.

The reason why blackout film works so well with wonky shaped windows is that you can customize the shape yourself by cutting the film into the shape of the window you are trying to darken.

For instance, if you had a hexagon-shaped window that you were trying to blackout, you would simply measure the size of the height and length of the window, mark those dimensions on the sheet of blackout film and then cut out the shape of the window. If your film is too small to fit the dimensions of your window, you may need to cut out individual pieces of the film to place together on the window.

When taking the measurements of your window and then marking those dimensions on the blackout film, keep in mind that it is incredibly important that you cut the film according to the exact dimensions of the window. If you cut the shape out to be too small in size, sunlight will seep out along the edges of the film, which will defeat the purpose of the blackout film. In turn, it is always a good idea to cut out a slightly larger shape than you need and then make adjustments later so that the shape fits the window more perfectly.

Other (less appealing) ways you can blackout wonky shaped windows…

tin foil on windows

Although using blackout cellular shades and blackout film are two of the easiest and most effective ways to blackout oddly shaped windows, there are a few other alternative ways in which you can blackout windows.


Blacking out your windows with paint can be an effective room darkening solution. Two coats of jet black paint on your window is a sure-fire way to block any sunlight from coming through to your house.

As you can imagine, however, there are a few downsides to this method. The first would be that using black paint on your windows is a rather permanent blackout solution. It is pretty difficult to scrape paint off of glass once it has dried. You would be better off just buying new windows if you wanted to see through your windows again. There are brands that advertise that their paint is made to peel right off but regardless, trying to remove paint of any kind from glass is still tricky business.

Secondly, applying the paint can be a messy process. If you aren’t careful. Be sure that you line the edges of the windows with painters tape and place plastic sheets below you to catch any falling paint.

Trash bags or tin foil

Using black trash bags or tin foil is a cost-effective way to block light from your windows. For either material, you need to make sure that it stretches across the length and width of your window first. Next, you can then use tape to secure the edges of the material around the frame of the window.

The downside to this method is that it can look a bit trashy (no pun intended). Not too many people want to live in a house where there are trash bags or tin foil blocking the windows.

Blackout curtains

Blackout curtains are one of the best solutions for blocking out light coming from your windows. The only problem is that most blackout curtains are designed just for standard designed windows. Windows that have particularly unusual shapes may not pair up very well with blackout curtains or curtains in general. 

That being said, blackout curtains might not be the best fit. However, if it looks as though blackout curtains can accommodate your windows despite their shape, then, by all means, give it a shot.

Final words

Whatever method you choose to darken your oddly shaped windows, just remember to be careful as you follow that method.

Unusually shaped windows are often more difficult to deal with simply because they don’t fit the standard shape that most people are used to. It is still completely doable to treat these windows, but it may just take a bit of extra time and care to do so.

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