Rugate technology is a powerful and flexible technique, particularly suited to Head-Up Display, HUD combiners and display visors. The thin film coating, applied to a combiner surface, reflects the symbology from a HUD, while simultaneously allowing a clear view through the combiner to the outside world. The coating is colour selective, only reflecting a narrow band of green coincident with the P53 display phosphor. It exhibits major advantages compared to other HUD technologies. Namely, reflects only CRT wavelengths, transmits the outside world with high efficiency and minimal colouration, has high photopic transmission, displays brightness insensitive to head movement, has wide angular response, weighs approximately half that of equivalent holographic combiners and offers a lower cost solution.