Window film, what is it?

You may understand window film to be window tinting. Are they same thing or are they different? In essence, they are exactly the same thing. However, it may be more common for the term ‘window tinting’ to be related to the automotive industry and the term ‘window film’ to be related to architectural glass, or flat glass.

Window film is made from polyesters, which includes a self adhesive for adhering to glass surfaces. It is designed to be used as an aftermarket or retrofit application for homes, buildings, automobiles, boats and other recreational vehicles or equipment.

Polyester is the raw material of choice due to its durability, strength and the ability to accept a variety of of other materials. The most commonly accepted materials are sputtered metals, dyes, adhesives, pigments and UV inhibitors.

Most commonly, the window film is offered through professional installation services but also comes in a variety of DIY product offerings, with limited scope and material size.

Primary uses of Window Film

The use of window film can be found in many market segments and purposes. There are many real world challenges with architectural glass that window film is designed to solve, along with automotive glass.

Window film is most commonly used as a retrofit product but has been used in certain OEM applications. Usually, window film addresses the following problems;

Window film provides a great degree of protection for all of the above purposes, especially when it comes to ultraviolet light protection. Becomes of its impressive ultraviolet light reduction properties and the ability to block certain light wavelengths from the sun, window film is most commonly used to reduce energy costs, interior temperature and limit the amount of fade damage caused by the sun rays.

Its important to note that window film is the most cost effective solution in comparison to all the competitive products on the market, including window replacement.

What specifically can window film do?


Heat Reduction

Window film is commonly used to reduce the amount of heat passing through glass from the Sun’s energy. They are most commonly applied to the interior of glass windows and surfaces and notably there are window films that are designed to be installed on the exterior surface of glass. (LINK exterior window films) Along with heat rejection, window films help reduce the amount of infrared, visible light, and ultraviolet radiation (UV). These window films are commonly made with a dye or some kind of metallization, enabling it to either absorb or reflect the sun’s energy back through the glass to the outside.

Notably, there currently is only one solar window film on the market that does not use any kind of metallization to reflect the sun’s energy. That product is made by 3M and is called Prestige Series for architectural applications and Crystalline for automobiles.

These modern window films help with the common problem of traditional window films that contain dyes and avoids the problem of discoloration. These window films cost considerable more than traditional window films but allow far more visible light to enter through the glass.

Solar radiation that is blocked by window film can be divided into three parts: visible light, which you see, infrared light, the energy you feel, and ultraviolet rays. Window film works as a filter to regulate these types of light. The specific amount of light and heat rejected is dependent on the specific type of window film selected.

3M NV25 Window Film Installation


Security window films are clear polyester films designed specifically to increase the strength of the glass it is installed on. The specific reason for applying security films is to keep the glass from shattering during a strong impact from various kinds of objects. Security window film, while mostly used in commercial environments, is now used in homes to help prevent and slow down intruders, or protect from shattered glass during a severe storm or earthquake.

More robust and stronger security films are even used for blast mitigation, which helps prevent glass fragments that are produced from detonations from entering occupied areas.

These window films can also be used for commercial retail storefronts to help slow down break-ins and robberies. Security window films can be applied to store doors, display cases and other large windows. The strength of this type of window films can also be increased by anchoring the window film to the glass frame itself, adding even more strength and protection. This method allows the film to absorb even stronger impact.

Some security films also incorporate dual properties, allowing them to also have solar protection properties built into them, increasing energy savings and cost efficiency.

Switchable Window Films

Switchable window films use a small electrical charge to change the appearance of the window film from clear to opaque at the flip of a switch. Although these product is still uncommon as of late there has been an increased interest in this product. Specifically for conference rooms and restrooms.

Some of the companies offering switchable window are ,

Privacy Films

Privacy window films can be used to obstruct the visibility through glass. Privacy film used for flat glass will be highly reflective, usually a silver reflection on the exterior, the high-lite side. The interior view, the low-lite side will remain unobstructed. Privacy window film may also be translucent but not transparent.

Privacy window films can also be used when correctly applied in the right scenario to create a one way mirror effect. Research has shown that in order for this method to be effective the light differential must be 6 to 10 times greater to achieve the desire result. As an example, a window during the day time is relative harder to see into but at night time when the lights are on in the interior seeing inside can be done with ease.

Decorative Films

Decorative window films or graphics films are generally frosted, patterned or colored. Some decorative films are gradient, striped, dotted, textured, or sand-blasted appearance.

Decorative films can also be used with computer aide cutting plotters to create unique original patterns such as logo, pictures and other images.

UV Window Films

Protection from the sun’s UV rays can be accomplished with clear and colorless window films. These films are designed specifically to target the UV spectrum of light either with the UV protection built into the window film polyester or the with UV inhibitors in the window film adhesive. UV can be measured in nano-meters (nm). Window films can filter our 380 nm to 400 nm.

Window Film and Fading

It is important to note that window film blocks 99 % of the UV lights however, UV is only one factor that contributes to fading from the sun’s rays. The other factors are solar heat, visible light humidity and other factors. The greatest protection from UV is window films that block all three.

The Facts About Fading & Window Film
Facts about fading from the sun’s rays and window film protection from UV


Correct Window Film Selection

How do you select the right window film?
When working with the ClimatePro™ team, we take special care to help you with the window film selection process. We make sure to identify your needs and expectations and then recommend the right products. To help you decide, we also have a complete collection of samples for you to examine.

Brands of Window Films

Window films are manufactured by a wide variety of manufacturers throughout the world.

Eastman Chemicals
Llumar Window Films
Vista Window Films
Huper Optik
Saint Gobain
Solar Gard
Panorama Window Films
Solar Graphics
HanitaTek Window Films
Aegis Films
Johnson Window Films
Scorpion Window Film
Nexfil USA
Maxpro Manufacturing
American Standard Window Film
Wintech Window Tinting

Window Film Associations & Groups

National Fenestration Rating Council (NFRC) Ratings

The National Fenestration Rating Council is a non-profit organization that provides standardized performance ratings for doors, windows, skylights and window films. Mainly the information the NFRC collects is to help determine energy efficiency for builders, architects, contractors, code officials and homeowners.

International Window Film Association (IWFA)

The International Window Film Association is a collective body of industry professionals such as window film dealers, distributors, and manufacturers. These professionals have a unified goal to grow the window film industry by creating accurate and unbiased research and promoting the awareness of window film.

European Window Film Association (EWFA)

The European Window Film Association focus its efforts in much the same way as the IWFA, only its target is the European markets.

Skin Cancer Association

The Skin Cancer Association recommends window films as an effective way to prevent skin cancer. Ultraviolet light can travel through car and home windows where you can get accumulative sun exposure that can lead to skin cancer and aging. UV blocking films can protect against this exposure.

Window Tinting State Laws

The summary chart of state aftermarket tint law information is not a legal document. It is the result of independent research, using several sources of public state documents. Window tinting laws vary from state to state and province to province. Before applying any window tinting materials, installers should thoroughly review the appropriate state regulations as well as local enforcement policies to insure compliance with all applicable standards. The following information is from the International Window Film Association.

  • FilmVLT%: Refers to the film itself
  • Net VLT%: Refers to the combined film & glass
  • Vague: The language of the law is unclear, legislative intent is unclear, or interpretation is uncertain.
  • Windshield: Presumably, NR tinting is permitted above the AS-1 line. If the law specifies only the AS-1 line, AS-1 appears. If AS-1 or specified inches appears, the AS-1 is assumed and only the number of inches down appears.(Note: NR is used in lieu of “No, Any, or a specific percentage” when the law permits unspecified “nonobstructive” or “Transparent” tinting materials. In these cases, the legality of tinting inevitably depends upon each officer’s discretion.
  • Front Sides: No film, or the actual percentage of VLT permitted. (Note: Because they may vary from state to state, manufacturer’s tolerances (i.e. + / – 3% VLT) are not listed on this chart, not are they included in these VLT numbers.)
  • MPV: Multi Purpose Vehicle, a vehicle with motive power, except a trailer, designed to carry ten people or less that is constructed either on a truck chassis or has special features for occasional off-road operation.
  • Back Sides: No film, or the actual percentage of VLT permitted.
  • Rear: No film, or the actual percentage of VLT permitted.
  • % of Reflectivity: NR No metallic or mirrored appearance
  • NE: Not excessive (not specific)
  • MNIR: Must not increase reflectivity
  • MBNR: Must be non-reflective (not specific)
  • NMMA: No metallic or mirrored appearance
  • NONE: No reference to reflectivity in the current law
  • Restricted Colors: R (Red), A (Amber), Y (Yellow), B (Blue), G (Gold), BK (Black), N/S (Not specified)
  • Mirrors (Left & Right required outside): YES or NO.*
  • Certification Required: YES or NO.#
  • Stckr/Loc: Sticker Location | NO: No sticker is required
  • Recommend: Sticker is recommended; can assist officers in identifying legal tint more easily.
  • Specific Locations: The State requires unique language & design, which may entail precise wording and sizing.
  • Driver: The sticker is required between the film & glass on the driver’s side window.
  • Door: The sticker is required on the inside of the driver’s side doorjamb.
  • All: The sticker should be put between the film & glass on each tinted window.
  • Medical Exemption: YES or NO.**

*Note: Usually, a YES means that dual outside mirrors are required if the back window is to be tinted.
#Note: This refers to a requirement for manufacturers to certify the films they plan to sell before shipping them into the state.
**Note: For more details about the specific terms of the exemption, consult the law.

Download (PDF, 751KB)

Under Construction
This section is currently under construction, check back as we add more states.

California Window Tint State Laws

Share this Post

Window Film Myths

Myths and Facts of Window Film

Myth #1 – Window films will cause your glass to break.

Window film itself does not cause the glass to break. Typically, if there is a break in the glass after window film is installed there may be other factors that contributed to the issue. There can be hidden things contributing to the stress found on the glass window, such as shifting in the building structure, improper window installation, and using the wrong kind of window film can cause glass to break. Also, as a protection most window film manufacturers offer a warranty against glass breakage.

Myth #2 – Window films make the interior of a building or home too dark.

Many years ago this may have been true but new modern day window films, focus on specific wavelengths of light such as infrared heat but still allow a large portion of the visible light to transmit through the window.

Some building owners and engineers have had concerns about window film reducing too much visible light and this would cause them to have to use more energy by adding more artificial light. However this is far from reality, the reason being is when window film is used employee and tenant comfort is increased. The work or living area is cooler and there ends of being less glare than before, so people open the window shades and blinds instead of keeping them closed. This allows more light in during the day, which reduces the amount artificial light needed.

Myth #3 – Window film makes windows look too shiny or iridescent.

Older, conventional types of window film can display an iridescent appearance when installed near certain types of energy-efficient lighting (such as compact fluorescents); however, newer window films are available that virtually eliminate this iridescence and shine.

Myth #4 – Window film will stop fading completely.

While window film does an amazing job to filter out the sun’s harmful rays and prevent a large portion of the sun’s solar heat and visible light. It cannot eliminate the effects of fading 100%. It will however help dramatically prolong the life of your furnishings and interiors valuables, especially in comparison to untreated glass.

Myth #5 – Installing window film is easy and anybody can do it.

Not true at all. Trust us we have first hand experience. When watching a trained professional it may look easy, but one mistake can easily lead to a very poor installation. Window film can easily be contaminated by a number of different facts and can be impossible to correct once this happens. Window film is not cheap itself, within seconds a perfectly good piece of window film can be ruined causing not only headache and frustration but a big hole in your pocket book.

For more window film myths please review this page.

Share this Post

Common Industry Terms

Visible Light Transmission (VLT) – The amount of visible light that passes through the glazing system, expressed as a percent. A lower VLT rating tends to be better for glare control, while a higher rating is preferred for maintaining natural light.

U-Value – A measurement of heat transfer through film due to outdoor/indoor temperature differences. The lower the U-value, the less heat transfers. When using performance data, a lower U-value is desirable for heat management.

Ultraviolet Light (UV) – Invisible, powerful wavelengths (shorter than light but longer than X rays) emitted by the sun separated into three types, UV-A, UV-B and UV-C. UV-B causes sunburn, and prolonged exposure can cause skin cancer. Window films block nearly 100% of ultraviolet light from passing through glass. The Panorama window films are approved products of the Skin Cancer Foundation.

Total Solar Energy Rejected (TSER) – Measures the window film’s ability to reject solar energy in the form of visible light, infrared radiation and ultraviolet light. The higher the TSER number, the more solar energy is rejected way from the window.

Spectrally Selective – Spectrally selective window films block only select wavelengths of radiation while maintaining a high amount of visible light transmittance. These premium films keep out the heat you don’t want and let in the natural light you love.

Solar Transmittance – The amount of solar energy (visible, infrared and ultraviolet) that passes through a glazing system, expressed as a percent.

When sunlight strikes glass, solar energy is either transmitted through the pane of glass, absorbed by the glass or reflected away from the glass. The type of glass and window film applied causes varying transmittance results, shown as a percent – this is the amount of solar energy that entered through the glass and film. Always refer to a manufacturer’s film-to-glass installation recommendation.
Solar Reflectance – The amount of solar energy (visible, infrared and ultraviolet) that is reflected by the glazing system, expressed as a percent.

When sunlight strikes glass solar energy is either transmitted through the pane of glass, absorbed by the glass or reflected away from the glass. The type of glass and window film applied causes varying reflectance results, shown as a percent – this is the amount of solar energy that the glass and film rejects away.

For maximum heat rejection, look for films with a high solar energy reflectance rating. Always refer to a manufacturer’s film-to-glass installation recommendation.

Solar Heat Gain Coefficient (SHGC)- The percentage of solar energy directly transmitted or absorbed and reradiated into a building. The lower the SHGC, the better the solar control properties of the film.
Solar Energy – Energy from the sun that is represented by visible light (glare), infrared radiation (heat) and ultraviolet radiation (fading and health hazards). Each form of energy is differentiated by its wavelength.

Solar Absorptance – The amount of solar energy (visible, infrared and ultraviolet,) that is absorbed by the glazing system, expressed as percent.

When sunlight strikes glass, solar energy is either transmitted through the glass, absorbed by the glass or reflected away from the glass. The type of glass and window film applied causes varying absorptance  results, expressed as a percent – this is the amount of solar energy that the glass and film retains. Always refer to a manufacturer’s film-to-glass installation recommendation.

Shading Coefficient (SC) – The ratio of solar heat gain passing through a glazing system to the solar heat gain that occurs under the same conditions if the window was made of clear, unshaded double strength glass. The lower the SC number, the better the solar control efficiency of the glazing system.

Emissivity – A measurement of a surface’s ability to absorb or reflect radiant energy. The lower the emissivity rating, the better the insulation characteristic of the glazing system in regard to heat loss. For windows with film, emissivity refers to the heat reflected back into the room. When using film performance data, lower emissivity ratings are preferred to minimize interior heat loss.

Clear Dry Adhesive (CDA) – A mounting adhesive that uses water to activate and form a chemical bond between the glass and film, adhering the film to the glass during installation. This adhesive offers a strong bond, film clarity and longevity.

Pressure Sensitive Adhesive (PSA) – A film mounting adhesive that uses pressure to form a mechanical bond between the film and glass, adhering the film to the glass during installation. Pressure sensitive adhesive is tacky to the touch. All automotive window films and safety window films incorporate PSA.