Lots of time when you stretch your film, you apply heat almost at the same time. But in case you have not been aware, there is a wrapping method called Cold Pre-stretch, which you apply the film in room temperature, stretch it “cold”, at last you heat it to trigger its memory effect.
We have written you an article about the importance of post heat - if you do not post heat your film, your film is very possibly going to shrink back at some point because of its memory. However, this cold pre-stretch technique truly just kind of makes the memory the best.
Just over a decade ago, a German and Japan group found out a pre-stretch technique. But there is one disadvantage, which is it could only be applied when it comes to gloss, matte, gloss/ matte metallic films. So here is the good news: the technique we are talking about here today is not that limited as the one from the past.
And this method is certainly worth a shot especially when you come across the most difficult parts during vehicle wrapping, for instance, corners, curvy mirrors and door handles.
Basically how it works is… you find out the hardest part of the hardware you want to wrap, and start from that point (instead of a flat surface). Let’s now use a curvy mirror as an example to see how we should apply this technique.
For a curvy mirror, the back side usually has the steepest surface. Thus, first anchor your film at that most difficult point, make sure there is equal film on each side of the mirror, because the next step you do is to pull and stretch the film with the commonly applied triangle technique.
Pull the film firmly onto the main surface of the mirror. You can then use your finger to flatten out the tension (the tension of the film is now shifted to the flatter area), but keep it about one inch from the edges, because by now, your film has been stretched two to four percent or so.
And here comes the magical time: Now that the film is settled on the mirror, grab your heat gun to heat it so that the memory effect can be triggered. In this way, the film is now relaxed onto the edge (also meaning the stretch is now back to 0 percent).
Instead of a tense and sharp wrinkles appearing on the edges, what you see now should be very soft if you have done it properly. Cut away the excess film nicely, this film is going to stay there for years, and you do not have to worry about peeling, lifting or whatever.