Skip to main content

How to Block Light From The Sides of Blinds and Shades

Bali cellular shades on a window in a kitchen.

Blinds and shades need room to operate, and there must be some space along the sides of the window treatment. This space between the window trim or wall and the vertical edges of the window treatment allows the shade or set of blinds to lift and lower smoothly. That’s why taking proper measurements for your blinds and shades is so important. A quarter-inch error can mean the difference between a fully operational shade and one that won’t go all the way up or down. Fortunately, making perfect measurements is easy. Check out Bali’s guides to measuring for blinds and shades.

If measured correctly, the gap between the wall or trim and the window treatment is less than a quarter of an inch—often much smaller. A tight squeeze. But even though it’s a relatively small gap, a lot of light can get through. Most of the time, it’s not a very noticeable amount of light. But when you’re trying to sleep, that light can be a real nuisance. Luckily, there are two easy solutions.

Bali room darkening side channels on windows in a bedroom.

Room Darkening Side Channels

If you’re using pleated or cellular shades, room darkening side channels are your best option for blocking out light along the sides of your shades. A side channel is easy to install. It is simply a track that guides the shade as it lifts and lowers. Because it angles around the front and back of the shade, it blocks the light that would have seeped through along a bare shade edge. The result is a darker room. And if you’re using a cellular shade in a blackout fabric, you’ll have an incredibly dark room.

Bali curtains and drapery on windows in a bedroom.

Custom Fabric Drapery

Layering drapery over blinds and shades is another great way to block the light that sneaks into the room along the edges of the window treatment. Simply hanging a set of room-darkening drapery over your shade or set of blinds takes care of almost all the nuisance light. Using drapery made with blackout fabrics or with blackout liners is the most powerful way to block out the light.

Using drapery this way has the added benefit of bringing additional color and texture into your room. There are hundreds of fabric options to choose from—making it easy to find just the right color and pattern for your design scheme. And adding drapery provides depth, visual interest, and even drama.

As we discussed earlier, the light that seeps in along the edges of your blinds and shades isn’t something most people notice. But in the rooms where you’re trying to sleep, work on a computer, or watch a movie, that nuisance light can be a real pain. With room-darkening side channels and drapery, you can easily block the light and enjoy better sleep, work, and entertainment.