color with and without the glass. A slight greenish tint will indicate the presence of iron oxide in the raw materials used to produce clear float glass. Additional transmitted colors may result from the absorption of any applied coatings. Light Transmission - the lower the light reflection and light absorption, the higher the light transmission, and therefore, the visibility of the objects displayed behind the glazing. Reflected Color - Uncoated glass reflects light uniformly and does not cause reflected light to be distorted (a white light source reflected in a non-coated glass pane will still appear white). However, anti-reflective coatings typically cause some wavelengths of light to be reflected more than others, causing a shift in the reflected color. This way, a white light source reflected in an anti-reflected glass surface may appear green or blue or red, depending on the wavelengths that are favored by a particular anti-reflective coating design. Intensity of Reflected Color - intensity of reflected color can be measured by its relative distance from the color neutral zone (i.e. white). Due to the variability of industrial processes, some producers design their anti-reflective coatings to have more intense colors so that the statistical deviation of outcomes falls within a specific color (green or blue, etc.). The tighter a manufacturer's control of its processes, the closer the design can be to the color neutral zone, without crossing over from a designated color. Reflected Color under an Angle - as a reflected light source is reflected from the glazing under a shallow angle, some anti-reflective coatings may cause the reflected color to shift. Therefore, in picture framing, a stable color under a wide viewing angle is desirable. Cleaning - since anti-reflective coatings render the glass surface virtually invisible, the dirt or soiling of the surface is much more visible on an anti-reflective surface. This enhanced visibility of surface smudges results in an end-user difficulty to clean the AR-coated glass. Therefore, some anti-reflective coatings have special surface treatments to improve cleanability, while others give special cleaning instructions to avoid damage to its coating. Handling - Some coatings are more durable than others. A scratch through an anti-reflective coating is also much more visible than a scratch through the surface of an uncoated glass due to the difference in the reflectivity of the scratched surface (for glass, about 8%) and the reflectivity of the anti-reflective surface around the scratch (about 0.5%).