Here is an interesting fact that you may not have known: automotive window tinting has been around since World War II started. The popular manufacturer back then was EZ Eye Factory Tint. Since they were the only proper company that could manufacture window tint films, some people tried to make their own DIY window tint using a spray that didn't have the same effect. In most cases, the tint would be uneven, and the consistency fell away throughout the entire car window. With this said, the first real window tint was invented back in 1966.
So, what exactly is automotive window tinting, why do people opt to tint their car's windows, what are the laws surrounding the application, and how do you apply a window tint? Don't worry; we have you covered with our ultimate guide to tinted windows for your car.
What Are Window Tints?
Window tints are made from a thin laminate material. It can be applied on the interior or exterior of glass windows in a variety of vehicles. Usually, window tints are made from polyethylene terephthalate (PET), which is a thermoplastic polymer resin related to the polyester family. PET is commonly used because of its clarity, dimensional stability, tensile strength, and ability to accept various surface-applied treatments.
Window tints are generally categorized according to their construction components, including:
1) Dyed 2) Metalized 3) Carbon 4) Ceramic 5) Crystalline 6) Carbon
Dye-Based Window Tint Film
Window tint film was initially "dye-based." However, this wasn't effective since it didn't have good heat control inside the car. This means that the car's temperature quickly rose, and the window tint didn't respond well to the rising temperature, causing bubbles and eventually peeling off the car's window.
Metalized Window Tint Film
Following "dye-based" window tint film was the second generation of car window tinting: metallic window tint films developed in the nineties. Metallic window films are infused with small metal particles to block the sunlight. This second generation of window tints provides a stronger resistance to shattering; however, heat control is still a problem.
A metalized film provides a rich shine and luster instead of a matte finish. The benefits of a metalized window tint include the following:
- It is effective in reducing glare.
- It has high heat rejection qualities.
- It can block a percentage of UV rays; however, it is not the best option for this benefit.
Ceramic Window Tinting
The latest generation of window tints available on the market today is ceramic window tinting. These films are highly durable and carry a life that lasts forever. Ceramic window tint films use small ceramic-based particles that are highly non-conductive. This means that they do not reduce electronic transmissions from Bluetooth, cellphones, Wi-Fi, and other communicative devices.
Ceramic window tints are excellent for blocking out sound and up to fifty percent of solar heat without visibility reduction.
Constantly exceeding expectations, ceramic window films for cars have UVA and UVB rejection with less tint to the film, which rejects harmful UV rays but still allows light in. The darker the tint, the higher the UV rejection.
Other benefits of ceramic window tints for cars include:
- Exceptional shatter-resistant qualities
- Reduced glare
- Blocks 99.9% of UV rays
- Available in multiple shades
With technology improving daily, vinyl wraps have also been introduced for window tinting and are quickly gaining popularity.
Window tints are also categorized by their intended use, by substrate type, and by their technical performance, for instance:
- Solar control
- Safety
- Security
- Privacy
The Benefits of Window Tinting
There are many different colors, shades, grades, and thicknesses available of window tint film, all of which offer solutions to several challenges. So, why do people tint their car windows? Let's explore some of the benefits of car window tinting.
- Heat rejection
- Glare control
- UV protection
- Thermal insulation
- Safety and security
- Daytime privacy
- Automotive styling
- Branding, decoration, and signage.
Window films provide a cost-effective solution to UV protection from harmful UV rays and heat rejection, especially in darker color cars that absorb the heat. Let's explore some of these benefits in further detail.
Safety and Security
In 2018 alone, there were 750,000 motor vehicle theft incidents. Thieves are more likely to break into your car if they can easily see something valuable. Privacy window film can help reduce the likelihood of thieves breaking into your car if they cannot see what is inside. 
And while daytime privacy for your personal belongings is a benefit, tinted windows could help save your life in a car accident. Nobody wants to be involved in a car accident, but they do happen, unfortunately. One of the main sources of injuries incurred in a car accident is shattered glass. Should you or one of your passengers hit the car window, shattered glass pieces could cause scratches, cuts, and other injuries.
Car window tints help create a thin film around the glass, which keeps the pieces together in the case of impact. The glass will still shatter, but the shards will stay together.
UV Protection
UV rays come from the sun and are a form of electromagnetic radiation. If you are exposed to these UV rays for an extended period of time, then your skin could develop burns and age prematurely. In many cases, UV rays are responsible for skin cancer.
Tinted car windows can provide you with UV protection. Most tinted windows are designed for car windows to block 99% of UV radiation. This means you are protected from the sun's harmful rays when driving your car, especially if you drive for many hours a day.
Prevents Upholstery from Fading
Just as UV radiation can affect your skin, it can cause the upholstery inside your car to fade and develop a pale color. A window tint can help prevent your upholstery from fading and helps protect the value of your car.
Heat Rejection
The sun is responsible for UV emission and head production, something we are all familiar with when we climb into a hot car on a summer's day. Hot days will often result in you having to use your air conditioner more often when driving. Using your air conditioner can reduce the overall performance of your car and affect your fuel consumption too.
Different types of window tints can prevent solar heat from building up inside your car since they act as an insulator for your automobile. This type of heat rejection keeps your car cooler on hot days and reduces your need to use your air conditioner.
Glare Control
Nobody wants to deal with glare when driving their car. Glare can deteriorate your driving experience and could pose a risk to your safety on the road. Tinted car windows can reduce the problem of glare. While you will not have a complete blackout of the light, glare control is enhanced with window tinting. It helps stop most of the glare from the sun and allows you better vision while driving.
Daytime Privacy
While tinted windows provide privacy for the personal items in your car, they also provide privacy for you and your passengers. This may not be the turning-point benefit to get tinted windows for your car. Still, some taxi companies and even limos will opt for tinted windows for their passengers' privacy, especially high-profile clients. Since limos are considered a MVP (multi-purpose vehicle), they are legally allowed to tint the rear windows with an almost pitch-black shade and completely blackout that window.
The wonderful thing about tinted car windows is that it limits others from seeing inside your car, but there is enough visible light for you to see outside clearly.
Decorative Window Film
Window tints come in various colors and shades. This gives you the freedom to customize your vehicle with decorative window film. You can make your window tint match the color of your car to create a unique seamless design.
If you do not want a vinyl sticker across your rear window to advertise your company, then you can customize your window film to advertise your brand. Custom printed window films are essentially frosted graphics and look like etched glass.
Window Tint Definitions
We cannot share the ultimate guide to window tinting without explaining some terms that describe specific attributes of window tint. Some of these terms may be technical and somewhat confusing, but we have broken them down intolayman's terms.
- Tint Darkness: Refers to the darkness of a window tint, which is measured by the visible light transmission percentage or VLT%.
- Front Side Windows: These are the two windows directly next to the passenger and driver seats.
- Rear Side Windows: These are the windows behind the passenger and driver seat. For vehicles with multiple rows of seats, such as SUVs, rear side windows refer to any windows on the doors behind the solid or front windows that are molded into the car's body.
- Window Shade Band: The top section of a windshield is referred to as the "eyebrow." The front windshield may be allowed to receive a window shade band across the windshield's top section. Different state laws dictate the regulations surrounding the window shade band.
- AS1 Line: An AS1 marking is made by each glass manufacturer and is a marking found near the top left or right side of the vehicle's front windshield. It certifies that the tinted window complies with Canadian or US transportation regulations. The AS1 line cannot be blocked in most cases.
- Tint Reflection: This refers to the reflective quality of a window tint.
Rules and Regulations of Car Window Tinting
With several benefits to back the popularity of car window tinting, there is also a drawback: if the tint is too dark, you limit your own visibility as a driver. Another factor is that while you are protecting your own privacy and the privacy of your personal items in transit, you are also limiting police and law enforcement from seeing into your vehicle.
For these reasons, every state has window tint laws and regulations that dictate how much tinting your vehicle is allowed on each of its windows. These laws regulate drivers on their window tint applications and keep everyone around them safe.
Each state has its own window tint laws and will refer to VLT, which stands for Visible Light Transmission. This describes the percentage of a window tint that allows light in. The windshield tinting laws will refer to the amount of the windshield that is legally tinted or the amount of tint allowed to be applied across the entire windshield, depending on the state's regulations.
Why is Window Tinting Illegal in Some States?
Most states in the U.S. prohibit window tinting because of safety and security. Tinted windows can limit the amount of light that enters your car and decrease the driver's visibility, especially if it is too dark. This limited vision can lead to increased vehicle accidents on the road and potentially infringe on public safety for federal and police agencies. If the tint is too dark, it can be obstructive to investigations and potentially dangerous during traffic stops.
California Window Tint Laws
While some states prohibit window tinting for cars and others have strict limitations, California is a state that favors tinted windows, especially since this state is sunny all year round. It is common in California for cars to have tinted windows, but specific requirements need to be met. Here are some of the laws you need to abide by in California:
- A tint that is green, gray, or neutral smoke in color must be used.
- There needs to be a VLT or luminous transmittance of at least 70%.
- It mustn't increase reflectivity for front and rear windows.
Front Window Tint Strip Law
The little strip on the top of the car's windshield is often referred to as the "eyebrow." This strip is often permitted to be tinted as long as it meets your state's laws. The eyebrow strip is small enough to allow the driver enough visibility while still getting added protection from the sun and glare.
VLT Percentage Differences
The restrictions on the amount of visible light transmitted into an automobile are measured and defined in percentages. The different percentages indicate the minimum amount of light that should enter through the car's windows.
If the VLT percentage is high, then the tint is light. A lower tint VLT percentage means that the window tint is darker. The legal percentage varies from one state to another. Below are some examples of the VLT percentage allowed in different states:
- Alabama: Allows 32% for front side windows, back side windows, and rear windows. Only 6-inches is allowed on the windshield.
- Arizona: Allows 33% for the front side windows and any percentage for the back side windows and rear windows. Tinting is allowed on the windshield to the top of the manufacturer's as 1 line.
- Colorado: Allows 27% for the front side windows, back side windows, and rear windows. Only 4-inches is allowed on the windshield.
- Connecticut: Allows 35% for the front side windows and back side windows, and any percentage for the rear windows. Non-reflective window tinting is allowed above the as-1 line.
- Delaware: Allows 70% for the front side windows and any percentage for the back side windows and rear windows. Non-reflective window tinting is allowed above the as-1 line.
- Georgia: Allows 32% for the front side windows, back side windows, and rear windows. Only 6-inches is allowed on the windshield.
- Hawaii: Allows 35% for the front side windows, back side windows, and rear windows. No inch requirement for the windscreen, except it must allow 70% of light in.
- Minnesota: Allows 50% for the front side windows, back side windows, and rear windows. Windshield tinting is not allowed at all.
- Illinois, Kansas, Maryland, Massachusetts, North Carolina, Oregon, Tennessee, and West Virginia: All allow 35% for the front side windows, back side windows, and rear windows with slight variations to the windshield rulings.
- New Jersey and Vermont: They do not allow any tinting for the front side windows, but any tinting is allowed for the back side windows and rear windows. Window tinting is allowed for the windshield to the top of the manufacturer's as-1 line.
Medical Exemptions
Believe it or not, some of these window tint laws can be "bent" for certain people with specified medical conditions that make them more sensitive to light. For instance, a person with albinism needs to be protected from UV rays.
Another example would someone suffering from Rosacea who may have increased sensitivity to the sun and be subject to an inflammation on their face when exposed.
With a doctor's letter, you could be allowed window tinting that would normally not be legal in your state.
Window Tinting Application
With some dealers charging labor of up to $500 for window tinting for your car, you may be considering the DIY approach to fit your car's window tint yourself. Keep the labor money in your pocket and try our application guide below.
What You Will Need
Below is what you will need for an automotive window tint application if you do not purchase a ready-made tint kit:
- Window tint film
- Window tint film application solution
- Lint-free cleaning cloth
- Razor knife
- A scraper blade
- An application squeegee
- A credit card
- A heat gun
The Application Process for Car Window Tinting
When you are preparing to apply window tint film to your car's windows, you need to make sure your working area is dust-free. You also need to ensure your working area is not too hot or too cold and there is little to no humidity. Most importantly, make sure you know your state's laws surrounding window tinting regulations.
Preparation
- Apply the window tint film application solution to the inside of your car's window. Make sure you do not overspray onto the door trims.
- Remove and debris, dirt, dust, and grime with the window scraper blade. Run the scraper blade across the window, from side to side. Start from the top of the window and gently make your way down towards the bottom of the window. This should be a gentle process; do not gouge the glass with the blade.
- Use a squeegee and clean the window from side to side. Start at the top of the window again and move down towards the bottom to clean away excess debris and solution.
Now that you have prepared your window for the window film tint, you can get started on the application.
Application Process
- Put the window tint film application solution on the outside of your car's window and carefully roll the window tint film over the window with the protective film layer facing upwards. The solution acts as static cling and will help hold the film in place so that you can cut your film to size. The solution also allows you to maneuver the film into place. To avoid the cutting process to get the film the right size, you could purchase precut window tint film. Run your squeegee over the tint to make sure it is firmly in place.
- For sliding windows, you need to roll down the window from the door frame approximately a quarter of an inch. Cut the sides and top of the film to size. Use your window as a template for the shape.
- Round the edges off neatly using your finger as a guideline.
- Slide the window tint film up, about half an inch, before you cut along the bottom of the window. You can use the window gasket as a template for cutting. By doing this, you ensure full coverage beyond the base of your car's window. If you have a non-sliding window, like a side window, use the window gasket as a template and cut the film right to the edges to ensure full coverage.
- Spray the inside of the car window with the window tint film application solution.
- Using a piece of clear tape, fix the film to the corner of the window and then carefully pull away the protective liner from the film. As you peel away the liner, spray the adhesive side of the film with an application solution.
- Discard the protective liner. Remove the film from the outside of your window and place it on the inside of your window. To avoid it touching the trim of the door, fold the bottom edge back into itself.
- Neatly move the tint into place at the top of the window. Ensure you leave a 1/8-inch gap at the top of any sliding window.
- Run your squeegee or credit card along the top of the window to remove air bubbles or water out of the top as you go along.
- Roll your window up again and spray your application solution on the window's film.
- Use your squeegee or credit card to hold the window gasket out while you slide the window tint film in underneath it.
- Once again, use your squeegee or credit card to push out the air and water bubbles out from beneath the film.
- Wrap your squeegee in the lint-free cloth and run it across your entire window. The lint cloth will absorb any excess application solution. Use the same cloth to wipe down your door trims.
- If you are struggling with any bubbles of trapped air or application solution in the film, you can use a heat gun to warm the troublesome area gently. Then use a squeegee or credit card to carefully push the bubbles out to the nearest edge of the window.
Repeat the process above until all of your car's windows have been fitted with window tint film.
For the cost of a few basic tools and materials, you can accurately complete your own DIY window tint application and save yourself a several hundred dollars that a professional installer would charge.
Window Tint Warranty
In most cases, you will get a warranty from your window tint provider. Generally, the warranty will cover discoloration, breakage, and other signs of deterioration that occur before the intended time.
The duration of your warranty depends on the type of window tint film you have purchased and the provider you bought it from. Most automotive window tint warranties last a lifetime. A reputable company or brand normally offers a lifetime warranty.
What Can Void Your Warranty?
There are several conditions where your window tint film warranty can be revoked or not even considered. For example, your provider may advise you not to wash your car several weeks after the application because it could tear your films. Should you go against this advice and wash your car, then damages caused will not be covered by your warranty.
Remember that your warranty does not stand in the instance of a broken glass window. Glass warranties are not the same as window tint warranties. Should your window be broken, it was not the result of the tinted film, so the warranty will not cover this scenario.
Concluding a Window Tint Purchase
One of the most important qualities you should look for when looking for a window tinting company is the warranty that the purchase carries. All window tint films come with a warranty; however, if you are using a professional installer to make the application, then make sure they provide a warranty for their work too. If the film starts to bubble, then it is not the manufacturer's fault but rather the responsibility of the person who installed it.
Other factors to consider include the following:
- The heat rejection rate of the film
- Aesthetic qualities of the film
- Your state's legal requirements and the VLT percentage
Window tints are not normally an expensive purchase, even for the higher-end brands. On average, you could expect to pay $100 to $400 to tint your entire car. But remember that lower-end tints are cheap, and aesthetically they may look cheap, too. Always choose the best quality you can find to protect the value of your vehicle.