This is one of the most complicated sections filmed for The Wrap Institute library. The engine vents have 5 vents one each side plus compound curves and raised objects. The risks to avoid are misalignment, silvering and getting too much tension in the "mouth" sections. See how Timm and Martin use a combination of the right mix of slip solution and starting at the right point to get even tension on the main area. To finish, note how they use a combination of distilled water and a squeegee change to feed all the tight mouths with no tension.