Do Blackout Curtains Block Out All Light? (Explained)

Blackout curtains are a type of window covering, that is made to block light from entering a room. They are very effective in making a room completely dark, which in turn has so many benefits.

These curtains can be expensive but they are a good investment because they are practical and functional, and still have some style.

Blackout curtains are designed to fully block light from entering a room. Good quality blackout curtains do block out all light.

Here is how blackout curtains block all light:

Blackout curtains have multiple linings to ensure that light does not enter. There is a white foam attached to the back of the fabric, then a black foam, and then another layer of white. This is why blackout curtains are so effective in blocking out all light.

Do Blackout Curtains Really Work?

Good quality blackout curtains really work.

These curtains are very effective and can completely block out light and make a room pitch-black.

Blackout curtains help mimic a night-time environment indoors that can help you sleep better.

Blackout curtains have a three-pass lining technology which ensures that light will not pass through them. This is made by applying three layers of lining to the curtain fabric to ensure that light does not enter the room.

Blackout curtains also work to eliminate background noise coming from outside the room. This is great especially if you want uninterrupted sleep and prevent noises from waking you up every now and then.

What Are Blackout Curtains Made Of?

Blackout curtains are generally made of two main components:

  1. the fabric
  2. and the lining.

Both components work together to effectively block out all light.


The best type of fabric for blackout curtains are thick and heavy ones that do not allow light to pass through. Semi-transparent fabrics are not recommended for blackout curtains.

Denser and opaque fabrics work really well to make blackout curtains.

The most commonly used types of fabric for blackout curtains are polyester and nylon.

Polyester is a popular fabric choice for blackout curtains. Some manufacturers use a polyester and cotton blend. Polyester is a popular choice for blackout curtain material because its fibers are durable and resilient.

It also costs less compared to other types of fabrics.

Since polyester is a type of plastic, it is naturally translucent but it is dyed to make different colored fibers. Polyester can hold up dye really well, and it would not fade even under direct exposure to sunlight.

Polyester fabric is quite easy to clean and maintain. You can even put it in the wash, as long as you run a gentle cycle on it with a mild detergent.

Polyester can also hold out well against wrinkling and shrinking.

Nylon is another popular fabric choice for blackout curtains. Just like polyester, nylon is a type of plastic synthetic fiber. The fibers of nylon fabric are a bit thinner but they are flexible and strong.

Nylon fabrics are soft, but they can hold up their shape well and can resist wrinkling. The fibers are lightweight, yet they are very durable.

Nylon fabrics are also easy to wash.

Blackout curtain fabrics do not necessarily have to be colored black. The fabric can come in any color – from light neutrals, like ivory and beige, to dark shades of blue, red, green, and many other hues.


The curtain fabric is not enough to block light. The lining is an essential part of blackout curtains. These curtains normally have three linings, which make up the three-pass blackout technology.

The blackout effect is achieved by attaching a layer of white foam to the back of the curtain fabric.

Then a black lining is added and then followed by another layer of white.

The white layers work to prevent the black lining from messing up the design or the decorative aspect of the fabric. Meanwhile, the black layer works to block the light and help retain the heat.

The three-pass blackout technology with the thick curtain fabric is what makes blackout curtains so effective.

How Thick Are Blackout Curtains?

Blackout curtains are thick enough to block all light from entering the room.

They are made of thick and heavy fabrics, with three layers of the lining so they can provide that desired blackout effect.

These curtains are noticeably thicker than sheer curtains and ordinary curtains.

Are Blackout Curtains Good For Your Sleep Schedule?

One of the many benefits of blackout curtains is that they can help improve your sleep.

Blackout curtains can make a room completely dark, even when it is in the middle of the day. Because of this, blackout curtains can scientifically improve your sleep.

When it is dark, our pineal glands secrete melatonin at a faster rate. This is why we feel more sleepy when our surroundings are dark.

Given these facts, blackout curtains can actually help induce sleep. Blackout curtains can make your room completely dark, thus causing your body to create more melatonin to make you feel sleepy.

This is how blackout curtains can be good for your sleep schedule, which is especially helpful if you work the night shifts and have to sleep during the day.

Blackout curtains can help you fall asleep faster. They can also help you sleep longer and uninterrupted, thus improving the overall quality of your sleep.

Can Blackout Curtains Save Energy Costs On Heat Or Air?

Another benefit to having blackout curtains is that they can help you be more energy efficient. Blackout curtains can actually help reduce your electricity bill by up to 25%.

When it is winter, blackout curtains can help warm up the room by keeping the cold air out and keeping the heat in.

This can decrease and even eliminate the need to use a thermal heater in the room.

When it is summer, blackout curtains can reflect the heat. This is to keep it out of the room and make the room feel cool. This can reduce the need to turn on your air-conditioning or cooling appliances.

Since blackout curtains can help insulate your room, they can help you save energy costs.

Are There Blackout Blinds Alternatives?

Blackout blinds are good alternatives to blackout curtains. Blackout blinds are usually made up of a single opaque fabric. They can be operated by using a remote control to lower or raise the blinds or manually with the use of a rod or wand that is attached to the blinds.

Manual blinds, of course, are cheaper.

Blackout blinds are a good option if you want window coverings that take up less space.

If you have a small room and you do not want it to feel stuffy, blinds are a great option.

There are more pros to using blackout blinds. They are more affordable compared to blackout curtains, and they are easier to install. Plus they are easier to clean.

However, blackout blinds do not offer a lot of decor options. They look clean and simple and usually come in a plain solid color. They are great for minimalist spaces.

Blackout blinds are great for blocking out a significant amount of light in order to darken a room.

But they do not completely block out all light.

If you want window coverings that can block 100% of the light that enters a room, blackout curtains are still the best option.

Blackout curtains are your best bet if you want window coverings that can block out all light. They are the most effective type of window covering for darkening a room.

Blackout curtains may be more expensive compared to other curtains and window coverings, but with all the benefits they provide, they are worth it.


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