Why does window tint 'bubble'

When windows have been tinted, the first thing the solar radiation hits once it has passed through the glass is the adhesive system that bonds the tint to the glass.

Ultra Violet  (UV) inhibitors are part of the adhesive system, and they are there to protect the adhesive and the film substratas from deterioration due to UV. Virtually all tints available offer 98%+ UV rejection when fitted to windows.

In basic terms; UV inhibitors work by absorbing the UV radiation, which unfortunately results in the gradual and progressive destruction/loss of these inhibitors.

Eventually there is little UV protection left and the adhesive starts to 'break down' resulting initially in blurred vision through the film. As the deterioration progresses the 'rotting' adhesive forms gas pockets between the glass and the film, resulting in the appearance of 'bubbles'.

This will eventually happen to all window tint and films, regardless of quality. However, during this time the car upholstery or home/office furnishings have been protected from the most damaging effects of UV radiation - retinting windows is usually far cheaper than replacing uphosltery and furnishings.

What people see quite often is bubbled tint on newer cars; this is usually the most basic dyed only film and deterioration can happen within 3 - 5 years of installation.

These basic films are usually installed on new cars as a 'dress up' by vehicle dealers; however many vehicles are fitted with higher quality metalised films (more UV inhibitors) which can have a lifespan of around 8 - 10 years and as such go 'unnoticed' as far as bubbling is concerned.

Domestic or commercial films as used on home/office windows generally have a lifespan of 12 - 20 years.

The reason car films in general have a shorter lifespan than domestic/commercial films on homes & offices is due to car windows being on more of an incline, and thus the film is exposed to greater solar radiation than home or office windows. Most home windows are also shaded for several hours per day by the roof eves, and are thus protected from a significant amount of solar radiation.