Windy conditions or unfavorable weather is most often the cause of ruined vinyl. Choosing a proper surface should also be a large consideration when choosing a place for your vinyl. Ideally, the surface will be smooth and glossy and wiped down of dirt and grime. When measuring your lettering in the design tool, remember that the lettering is measured from the top of the letter to the bottom of the lowest hanging letter, like a y or j. If you’re applying a graphic or lettering to the back of your window, remember the vinyl is intended to adhere to the front of the window. So would have to be flipped prior to production to ensure it adheres during installation.