Retroreflective sheeting is flexible

retroreflective A retroreflector (sometimes called a retroflector or cataphote) is a device or surface that reflects radiation (usually light) back to its source with minimum scattering. This works at a wide range of angle of incidence, unlike a planar mirror, ...

material primarily used to increase the nighttime conspicuity of

traffic sign Traffic signs or road signs are signs erected at the side of or above roads to give instructions or provide information to road users. The earliest signs were simple wooden or stone milestones. Later, signs with directional arms were introduce ...

high-visibility clothing High-visibility clothing, sometimes shortened to hi vis or hi viz, is any clothing worn that is highly luminescent in its natural matt property or a color that is easily discernible from any background. It is most commonly worn on the torso and ...

, and other items so they are safely and effectively visible in the light of an approaching driver's

headlamp A headlamp is a lamp attached to the front of a vehicle to illuminate the road ahead. Headlamps are also often called headlights, but in the most precise usage, ''headlamp'' is the term for the device itself and ''headlight'' is the term f ...

s. 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.

Applications

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

High-visibility clothing

High-visibility clothing High-visibility clothing, sometimes shortened to hi vis or hi viz, is any clothing worn that is highly luminescent in its natural matt property or a color that is easily discernible from any background. It is most commonly worn on the torso and ...

frequently combines retroreflective sheeting with

fluorescent Fluorescence is the emission of light by a substance that has absorbed light or other electromagnetic radiation. It is a form of luminescence. In most cases, the emitted light has a longer wavelength, and therefore a lower photon energy, th ...

fabrics in order to significantly increase the wearer's visibility from a distance, which in turn reduces the risk of traffic-related accidents. Such clothing is commonly worn as (often mandatory) PPE by professionals who work near road traffic or

heavy machinery Heavy equipment or heavy machinery refers to heavy-duty vehicles specially designed to execute construction tasks, most frequently involving earthwork operations or other large construction tasks. ''Heavy equipment'' usually comprises five e ...

, often at night or in low-visibility weather conditions, such as

construction workers Construction is a general term meaning the art and science to form objects, systems, or organizations,"Construction" def. 1.a. 1.b. and 1.c. ''Oxford English Dictionary'' Second Edition on CD-ROM (v. 4.0) Oxford University Press 2009 and ...

, road workers and

emergency service Emergency services and rescue services are organizations that ensure public safety and health by addressing and resolving different emergencies. Some of these agencies exist solely for addressing certain types of emergencies, while others deal wit ...

personnel. It is also commonly worn by

cyclists Cycling, also, when on a two-wheeled bicycle, called bicycling or biking, is the use of cycles for transport, recreation, exercise or sport. People engaged in cycling are referred to as "cyclists", "bicyclists", or "bikers". Apart from two- ...

or joggers to increase their nighttime visibility to road traffic.

For road signs

Retroreflective sheeting for road signs is categorized by construction and performance specified by technical standards such as

ASTM ASTM International, formerly known as American Society for Testing and Materials, is an international standards organization that develops and publishes voluntary consensus technical standards for a wide range of materials, products, systems, a ...

D4956-11a.; various types give differing levels of retroreflection, effective view angles, and lifespan. Sheeting has replaced

button copy Button copy is a type of physical design for road signs in the United States. Round plastic retroreflectors, retroreflective buttons made of transparent plastic are placed in rows following the contours of sign legend elements, usually painted whi ...

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 are further delineations based on material used and visibility distance. Diamond grade typically has the greatest distance for visibility of the three major categories.

For barcode labels

Barcodes A barcode or bar code is a method of representing data in a visual, machine-readable form. Initially, barcodes represented data by varying the widths, spacings and sizes of parallel lines. These barcodes, now commonly referred to as linear or on ...

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

In motion pictures

The special effects technique of

Front Projection A front projection effect is an in-camera visual effects process in film production for combining foreground performance with pre-filmed background footage. In contrast to rear projection, which projects footage onto a screen from behind the ...

uses retroreflective screens to create false backgrounds for scenes shot in studios. Front projection was used in '' 2001: A Space Odyssey'' during the "Dawn of Man" sequence. Other films that have used front projection techniques include ''

Silent Running ''Silent Running'' is a 1972 American environmental-themed post-apocalyptic science fiction film. It is the directorial debut of Douglas Trumbull, and stars Bruce Dern, Cliff Potts, Ron Rifkin, and Jesse Vint. Plot In the future, all plant l ...

'', ''

Where Eagles Dare ''Where Eagles Dare'' is a 1968 war film directed by Brian G. Hutton and starring Richard Burton, Clint Eastwood and Mary Ure. It follows a joint British-American Special Operations Executive team of paratroopers raiding a castle (shot on loca ...

'' and '' Superman''. ''

Star Wars ''Star Wars'' is an American epic space opera multimedia franchise created by George Lucas, which began with the eponymous 1977 film and quickly became a worldwide pop-culture phenomenon. The franchise has been expanded into various film ...

'' episodes IV, V and VI used retroreflective sheeting for the

lightsaber A lightsaber is a fictional energy sword featured throughout the ''Star Wars'' franchise. A typical lightsaber is depicted as a luminescent plasma blade about in length emitted from a metal hilt around in length. First introduced in the or ...

blades.

Autonomous vehicle navigation

Reflective tape is used to provide an explicit way to do

optical Optics is the branch of physics that studies the behaviour and properties of light, including its interactions with matter and the construction of instruments that use or detect it. Optics usually describes the behaviour of visible, ultrav ...

navigation of

autonomous vehicles Vehicular automation involves the use of mechatronics, artificial intelligence, and multi-agent systems to assist the operator of a vehicle (car, aircraft, watercraft, or otherwise).Hu, J.; Bhowmick, P.; Lanzon, A.,Group Coordinated Control ...

. For example, strips of retroreflective tape are used to provide

navigation Navigation is a field of study that focuses on the process of monitoring and controlling the movement of a craft or vehicle from one place to another.Bowditch, 2003:799. The field of navigation includes four general categories: land navigation, ...

inputs to the prototype

Hyperloop A hyperloop is a proposed high-speed transportion system for both public and goods transport. The idea was picked up by Elon Musk to describe a modern project based on the vactrain concept (first appearance in 1799). Hyperloop systems compr ...

pod vehicles on the SpaceX Hypertube test track.

References

{{Reflist, 30em Glass compositions Glass engineering and science Nonwoven fabrics Traffic signs