It is interesting to see the public perception of our trade. Some people have been aware of it since year dot, others are only just now becoming aware of the benefits our window films can give them. Looking at the costs of incorporating all the benefits into glass, window film is far more economical than anything else.
We install our products on old houses with old glass as well as on brand new double glazed homes or businesses. There is no wrong time or age to have this done.
In new homes, with clear double glazing, the need for tinting becomes evident the moment the sun is heating up the rooms. Although the glass industry still gives us a hard time, by suggesting that any film applied will invalidate their warranties, we have never had a claim in all the time we have been in business. Reality is, a well constructed system in conjunction with the right film will not fail. Care has to be taken in the choice of film, and a good knowledge of glass types is required to get it right. 
So, is tinting glass still popular? You bet! More than ever!

We come across a product called UV-XXXX. It is a coating that blocks UV, nothing else. It is sold to reduce fading. Does it work? Well, anything is better than nothing. But since fading is a combination of UV, heat, light and some other factors to a lesser degree, this kind of product is very limited in effectiveness.
Over time, this coating becomes almost opaque and real ugly to look through.
The owner of this unit has tried to remove it, as seen in the bottom left corner. It was taking forever!
We got called and in less than one hour, 3 large windows were back to normal glass to look through!

    This is a picture of window film with "banding".
The film is becoming streaky and is visible more at certain time of the year, usually in winter. This particular window film was installed around 16 years ago, so is well past its expected life time.

We removed all the film and adhesive and tinted it again with new film, without damaging the glass.

There is a phenomenon called "Refraction". It becomes evident when the sun is at a low angle and there is a dark background, when looking out. The moment the sun is higher in the sky, or no sun, the glass is clear to see through.I have seen it on clear glass and tinted glass. When using a conventional, metalised window film, refraction can happen.
How can you prevent or minimise this problem? We have found a high definition nano-ceramic film to do the trick. Ceramic film is perfect for this, although this film cannot be used on certain kinds of glass.y

You can see the difference in the pictures to the right.

The top picture is with standard window film on sunny day.
We replaced the film with a ceramic film and the result is shown in the
second picture.

I did a job yesterday, brand new home, with double glazed windows. The owners had a quote from another tinting company that usually specialises in car tinting. The tint they recommended was a car film to give the owner protection from the sun and privacy. Car film has to be non-reflective and naturally has a high heat absorption.  And this is where the problems start.....
Let me fill you in:
Double glazing is made up of two layers of glass, with an air gap between the layers. It is this gap that provides the insulation properties of double glazing. The glass can be any combination of clear or tinted, annealed (normal), laminated or toughened glass. Sometimes the air inside is replaced with Argon gas to enhance the insulating performance. One layer of the glass can also have a Low-E coating to either keep more heat in, or to keep it out. All around the perimeter, between the glass panes, is a "tape", usually with little holes.  Behind the holes is a desiccant to absorb moisture.

If a film is applied to the room-side of the double glazing, this pane will warm up in the sun. How warm it gets, depends on the film type used. Non-reflective film, such as car tints, have a high absorption rate of up to 70%. As the glass heats up, it expands. It also pressurises the air between the two panes. The risk here is two-fold. Firstly, certain glass types can crack. (Thermal stress) Secondly, there is a risk of air getting into the gap. This may only happen very slowly, but over time, it will show up as condensation between the glass, as the desiccant can only absorb so much moisture. This can happen without film being applied, but "stressing the glass" will accelerate this process. (Seal failure)
We have to use a film that has a low heat absorption to minimise the risk of thermal stress and seal failure. Generally, SV25, SV50 or the new Daydream range are the best film types for this.
So, if we suggest certain window films, it is not because we like them, but because they tend to be the safest options.
Please feel free to ask questions about this, or any other aspect of window tinting.

If you are in need of privacy, but don't want to lose too much light, SV25 is the film to consider seriously. Even in corner situations, where windows are on two sides, you get very good privacy.
Although somewhat reflective, it is not a mirror and blends in nicely in most places.  Just today I returned to a place where we applied some SV25. The lady did not tell her husband and it took him a few months, until he realised it was there. Typical male, we're all the same!

Window film is a complex product that has evolved over the last 40 years or so.
Think back to the early days (if you're old enough). All you got was a silver film. Adhesive had to be sprayed on, luckily before my time too.
Then there was the dyed polyester. Great to look at, but turning purple within a short time.... and still sold today at places like Repco and Supercheap as well as Trade Me and of course the cheap car tinting places.
Fortunately, some of us have moved on from this and offer genuine performance films.
Today's window film uses the latest technology and consequently is more costly to produce. The latest low-e film contains Gold and manufacturing plants had to increase security, for obvious reasons.
So why on earth are some people still going with the cheapest price??????
As the saying goes: "You get what you pay for"
Granted, just because one price is higher than another, does not guarantee a superior product. Therefore, ask questions.

Like anything in this world, nothing lasts forever!
I often get asked, how to remove window film. There are a couple of different adhesive types and depending what kind it is, the method changes a little.

First, car film, safety film, frosted film and some solar films are made with PS (Pressure Sensitive) adhesive. This means the film will adhere mechanically straight away. This glue is easiest to remove.
On cars, have the car outside in the sun, if possible to warm up the glass. Step 1: With a small razor blade or knife, peel away from one corner. Slowly! If you're lucky, the whole sheet will come off. Unfortunately, this is not the case very often. If it's hard to peel, stop and spray the film with glass cleaner containing ammonia. Use an old black plastic rubbish bag and place it over the film for a few minutes. This slows down the evaporation and softens the glue. Repeat step 1.
On rear windows with demister bars, ensure you don't use a scraper, otherwise you will damage the lines. You can use "Goldilocks" or similar non-scratch scouring pads.
Once all the film is off, you are left with a lot of glue. There are some adhesive removers on the market that work well, but care must be taken not to get any on upholstery or other surfaces. You can use glass cleaner and new razor blades and go over it a few times and it will come off.
If you get the car tinted again, ask them them to give you a price for removing it. If you do a bad job, leaving adhesive residue, they will probably charge you to clean it up anyway.
Have fun!