A:There are two reasons:1.Didn't squeegee away air bubbles. 2.Forget to remove backing protect film.
Solution:There are 2 layers of window film, one transparent protect sheet, the other face film which we used. Remove backing protect sheet and spring plenty water to glass. Do remember to squeegee away any bubbles.
Q2:Why edge of window film curl up? And have bubbles?
A:Maybe the corner glass is not flat.
Solution:Trim the edge, It's better to make sure the size of window film 0.3cm shorter than glass.
Q3:Why there are many bubbles in the film after application?
A:Water is not enough in spring process.
Solution:Peel off window film, respring water to glass. More water, more better. Then apply window film again.