Window Film Blog

What thickness of window film is the best for solar control?

If you have a room that is too hot to handle in your home and are considering solar control window film as a strategy to beat the heat, you want to know you are buying the best product you can to get the job done. One thing you may be wondering is what thickness of window film is best when solar control is your objective. Let’s get into it in this post.

What factors play a role in solar control window film performance?

When it comes to solar control, the thickness of the window film isn’t necessarily the determining factor. Instead, what really matters is what technology is used to make the film as well as the film’s performance specifications. It’s important to know both because they can vary greatly across different products and manufacturers.

Window Film Technology

Solar control window films come in three flavors based on the technology used to block solar energy.

Dyed Film

The first films were dyed films. They basically used the principle that dark colors absorb more solar radiation than light colors to absorb some of the energy coming into a window. Dyed films were a good first start, but their performance wasn’t great and they tended to fade or turn purple over time.

Metallic Film

The next generation of films used metals – often in conjunction with dyes to up window film performance. Tiny metal particles helped to reflect a portion of the solar energy and in combination with what was absorbed from the dark film, the result was a higher performing film that blocked more heat. The issue with metallic films is that some folks don’t like the shiny, mirror finish it gives their windows. In addition, metallic films can block some other electromagnetic waves.

Ceramic Film

The most effective solar control window films are those that contain ceramics. These materials are excellent at rejecting heat and solar energy, while also reducing glare. They have a beautiful neutral color that is aesthetically pleasing and won’t fade like dyed films. What’s more, ceramic films don’t block radio, GPS or other electromagnetic waves. This is why ceramic film is the professional choice for residential and commercial window film. Read more about ceramic window film.

Window Film Performance Specifications

Once you decide what type of film you are considering, the next thing to do is compare the performance specifications of the film. The National Fenestration Rating Council (NFRC) is the organization that sets the standards for window as well as window film performance. When you are looking at a film for solar control, there are two important measurements to consider TSER and SHGC:

Total Solar Energy Rejected (TSER)

TSER is an important metric in the realm of window films. In simple terms, it tells you the amount of solar energy a window film is designed to block or repel. Represented as a percentage, if a film boasts a 100% TSER, it means it completely rejects all solar energy. Often, the more dark or reflective a window film is, the higher its TSER percentage tends to be.

Solar Heat Gain Coefficient (SHGC)

SHGC is another key measurement, albeit it serves a slightly different purpose. While TSER focuses on the solar energy rejected, SHGC zeroes in on the quantity of solar energy that penetrates the window film. Another distinction is that SHGC takes into account the heat transmitted into a room, a consequence of the heating of the film and glass due to sunlight. A crucial thing to remember when comparing these metrics is that for optimal solar performance, you’d want a window film with a high TSER and a low SHGC.

Recently, many window film manufacturers are leaning more towards using SHGC as their preferred metric over TSER. But regardless of the chosen metric, understanding both helps ensure you pick the best window film for your needs. Whether it’s heat rejection or understanding the amount of solar energy that infiltrates your space, being informed is key.

Here are ComforTech™ Ceramic Series Window Film’s performance specifications:

ComforTech Window Film Specifications Chart

When looking for unbeatable solar control, we recommend ComforTech™ 25, ComforTech™ 15 or ComforTech™ 05 as the best choices. You can read about the differences between those three to help you decide.

Does window film thickness even matter then?

So, if window film thickness doesn’t matter for solar control, why should you care? Well, window film thickness does matter for other reasons:

Durability and Lifespan

Thicker films tend to be more durable and resistant to wear and tear, resulting in a longer lifespan. This can be particularly beneficial in high-traffic areas or where the film is exposed to frequent contact. Our ComforTech™ Ceramic Series film uses two layers of polyester, one with the ceramic particles and one clear to provide stability and durability to the film.

Safety & Security

While 2 Mil window film is not considered a true safety film, it does have some protective benefits. ComforTech™ film will hold glass together in the event of breakage reducing the risk of harm due to broken glass on the floor or furnishings.

Photo of a burglar getting ready to break a window to gain entry into a home for a post on safety window film

And while it won’t keep an intruder out, have a 2 mil film on your windows will slow a burglar down giving you precious extra time to alert authorities.

Ease of Handling & Installation

Perhaps the biggest benefit to DIYers of our thicker film is its ease of handling making installation easier. Thinner films tend to crinkle and crease much easier than thicker films. Our 2 Mil films are more forgiving and harder to damage, making installing them yourself that much easier. It’s the reason why most professional-grade films are 2 Mil. Learn how easy it is install window film yourself.


In conclusion, while the thickness of a window film can influence its durability and ease of installation, when it comes to solar control, the film’s material and specific properties are the key considerations. All of ComforTech™ Ceramic Series window film shades offer both solar control and the benefits of a professional thickness film. Learn more at

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