Adhesive defines crystal film screen appearance and lifespan. Cheap glue yellows, clouds, and delaminates in 1-2 years. Premium screens use anti-yellowing PU/silicone adhesives, UV & weather resistant, stable for 5-10 years. Installation requires vacuum degassing, uniform coating, edge sealing to avoid bubbles. Outdoor needs IP65+ and 4H+ scratch resistance. Superior glue ensures long-term clarity and landmark aesthetics.