All states have traffic laws that limit the amount of window tint on motor vehicles—often by specifying the amount of visible light transmission (VLT) that is required. VLT is the amount of light that is transmitted through the window and into the vehicle. For example, a 70%VLT means that 70% of light will pass through the window and 30% will be reflected. Thus, a lower VLT indicates a darker film or tint.

Another term to know is visual light reflection (VLR)—which is the opposite of VLT. VLR is the amount of solar energy that is reflected off the glass and away from the inside of the vehicle.

In most states tickets or citations for illegal window tint are known as fix-it tickets and the ticket or citation will indicate that it is a correctable violation of traffic laws. For example, if you fix the window tint problem within the required period, pay a small fine, and get the signature of an authorized person (a local police officer) the court may dismiss the ticket.

But if you fail to fix the window tint problem within the required period you must pay the fine for the violation and you may be issued another ticket that will be part of your driving record. And if you fail to pay the ticket or appear in court on the hearing date the court may issue a warrant for your arrest.

Window tint laws vary from state to state and some states have exemptions for certain vehicles such as limousines and recognize medical exemptions when the driver has a written statement from a licensed medical doctor, ophthalmologist, or optometrist.

In Texas, window tint laws are outlined in the Texas Transportation Code, Chapter 547, which specifies the allowed levels of window tint on vehicles to ensure safety and visibility. The state permits non-reflective tint above the manufacturer's AS-1 line on the windshield. For the front side windows, the tint must allow more than 25% of light in (25% VLT). The back side and rear windows can have any darkness if the vehicle has outside mirrors; otherwise, they must also allow more than 25% of light in. The law also specifies that the window tint should not be more than 25% reflective, addressing the VLR aspect. Texas recognizes medical exemptions for those who require a darker tint due to certain medical conditions, and these individuals must carry documentation to prove the exemption. If a driver is cited for illegal window tint in Texas, it is typically considered a 'fix-it' ticket, which means the driver can correct the violation and show proof to potentially have the ticket dismissed. However, failure to comply with the correction period can result in fines, additional tickets, and potentially a warrant for arrest if court dates are missed.