Retroreflective sheeting

Retroreflective sheeting is flexible retroreflective material primarily used to increase the nighttime of traffic signs, high-visibility clothing, and other items so they are safely and effectively visible in the light of an approaching driver's headlamps. They are also used as a material to increase the scanning range of barcodes in factory settings. The sheeting consists of retroreflective glass beads, microprisms, or encapsulated lenses sealed onto a fabric or plastic substrate. Many different colors and degrees of reflection intensity are provided by numerous manufacturers for various applications. As with any retroreflector, sheeting glows brightly when there is a small angle between the observer's eye and the light source directed toward the sheeting, but appears nonreflective when viewed from other directions.

Retroreflective sheeting is widely used in a variety of applications today, after early widespread use in road signage beginning in the 1960s.

Retroreflective sheeting for road signs is categorized by construction and performance specified by technical standards such as ASTM D4956-11a.; various types give differing levels of retroreflection, effective view angles, and lifespan. Sheeting has replaced button copy as the predominant type of retroreflector used in roadway signs.

There are several grades of retroreflective sheeting which include the three major grades - engineer grade, high intensity prismatic (HIP) and Diamond grade. Within these categories there are further delineations based on material used and visibility distance. Diamond grade typically has the greatest distance for visibility of the three major categories.

Barcodes can be printed onto retroflective sheeting to enable scanning up to 50 feet away.

Star Wars episodes IV, V, and VI, used retroreflective sheeting for the lightsaber blades

Reflective tape is used to provide an explicit way to do optical navigation of autonomous vehicles. For example, strips of retroreflective tape are used to provide navigation inputs to the prototype Hyperloop pod vehicles on the SpaceX Hypertube test track.

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