Along with proper brightness, a display must have high contrast for good readability. Contrast is the difference between the background’s “off state” (blank display area) versus the “on state” (illuminated display area). High contrast increases the readability of a message, much like white text on a black background, causing readers to focus on what needs to be seen. The highest contrast appears in a display with a dark border and a consistent dark black background across the entire display with minimal sunlight reflection. A louver system provides shading and black, non-reflective materials ensure the least amount of reflection. Polycarbonate or acrylic face material may provide as high a contrast as flat black paint or a black potting encapsulant.