OEM Reflective Aluminum Sign Combining durability with visibility, the Reflective Aluminum Sign is ideal for various applications, providing long-lasting and clear signage with reflective properties for enhanced safety. Details of Reflective Aluminum Sign The composition of custom reflective aluminum signs. Reflective films are divided into the following categories according to different reflective coefficients: Engineering grade (class I) reflective film High-strength reflective film (Class III) Super-class (Class IV) reflective film Diamond-grade (V-class) reflective film The higher the level, the better the reflection coefficient.