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Black light paint or black light fluorescent paint is luminous paint that glows under a black light. It is based on pigments that respond to light in the ultraviolet segment of the electromagnetic spectrum. The paint may or may not be colorful under ordinary light. Black light paint should not be confused with phosphorescent (glow-in-the-dark) or daylight fluorescent paint.
The invention of black light paint is attributed to brothers Joseph and Robert Switzer in the 1930s. After a fall, Robert suffered a severe head injury that resulted in a severed optic nerve. His doctor confined him to a dark room while he waited for his sight to recover. Joseph, who was a chemistry major at the University of California, Berkeley, worked with Robert to investigate fluorescent compounds. They brought a black light into the storeroom of their father's drugstore looking for naturally fluorescing organic compounds and mixed those compounds with shellac to develop the first black light fluorescent paints. [1] The first use of these paints was for Joseph's amateur magic shows. [2]
The brothers founded the Fluor-S-Art Company, later named Day-Glo Color Corp., to develop and sell their products. [2] ‘Day-Glo’ is a registered trademark of the Day-Glo Color Corporation. [3] The first commercial uses of black light fluorescent paints were for store displays and movie theaters. During World War II, black light fluorescent paints were used on U.S. naval carriers to allow planes to land at night. [2]
Black light paints and inks are commonly used in the production of black light posters. Under daylight, the poster may or may not be vibrant in color, but under black light (with little or no visible light present), the effect produced can be psychedelic.[ citation needed ] The inks are normally highly sensitive to direct sunlight and other powerful light sources. The fluorescent dyes cause a chemical reaction when exposed to high intensity light sources (HILS) and the visual result is a fading in the colors of the inks. With paper, significant visible change in the color saturation can typically be observed within 45 minutes to one hour of exposure to the HILS. To date, there is no absolute method to prevent this phenomenon, although certain laminations, lacquer coatings and glass or plastic protective sheets can effectively slow the fading characteristics of the dyes.
Other common usage of the black light pigments is in security features of money notes, various certificates printed on paper, meal coupons, tickets and similar things that represent a value (monetary or otherwise). The black light printed figures used for this purpose are usually invisible under normal lighting, even when they are exposed to direct sunlight (which contains ultraviolet light) but they show up glowing when exposed to black light source. This defeats simple and inexpensive attempts to counterfeit them by scanning the original using a high resolution scanner and printing them using an inexpensive high resolution printer (most if not all inexpensive printers do not allow using black light inks for printing)[ citation needed ] and no special equipment is needed to verify the presence and correctness of this feature (an inexpensive black light source being all that is required). Some coupons and tickets use colorful black light inks.
On many German locomotives the control panel labels were printed with black light paint and a black light source was provided in the cab. This left the driver with full night vision while still enabling him to distinguish between the different switches and levers to operate his locomotive.[ citation needed ]
Black light paints are sometimes used in the scenery of amusement park dark rides: a black light illuminates the vivid colors of the scenery, while the vehicle and other passengers remain dimly lit or barely visible. This can enhance the effect of being in a fantasy world.
Black light paints may be fluorescent or, more rarely, phosphorescent, containing a phosphor that continues to glow for a time after the black light has been removed. Black light paint can be mixed with similar shades of normal pigments, ‘brightening’ them when viewed in sunlight.
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, than the absorbed radiation. A perceptible example of fluorescence occurs when the absorbed radiation is in the ultraviolet region of the electromagnetic spectrum, while the emitted light is in the visible region; this gives the fluorescent substance a distinct color that can only be seen when the substance has been exposed to UV light. Fluorescent materials cease to glow nearly immediately when the radiation source stops, unlike phosphorescent materials, which continue to emit light for some time after.
Paint is a liquid pigment that, after applied to a solid material and allowed to dry, adds a film-like layer, in most cases to create an image, known as a painting. Paint can be made in many colors and types. Most paints are either oil-based or water-based, and each has distinct characteristics.
Ultraviolet (UV) light is electromagnetic radiation of wavelength shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight, and constitutes about 10% of the total electromagnetic radiation output from the Sun. It is also produced by electric arcs; Cherenkov radiation; and specialized lights, such as mercury-vapor lamps, tanning lamps, and black lights.
A pigment is a powder used to add color or change visual appearance. Pigments are completely or nearly insoluble and chemically unreactive in water or another medium; in contrast, dyes are colored substances which are soluble or go into solution at some stage in their use. Dyes are often organic compounds whereas pigments are often inorganic. Pigments of prehistoric and historic value include ochre, charcoal, and lapis lazuli.
Invisible ink, also known as security ink or sympathetic ink, is a substance used for writing, which is invisible either on application or soon thereafter, and can later be made visible by some means, such as heat or ultraviolet light. Invisible ink is one form of steganography.
A phosphor is a substance that exhibits the phenomenon of luminescence; it emits light when exposed to some type of radiant energy. The term is used both for fluorescent or phosphorescent substances which glow on exposure to ultraviolet or visible light, and cathodoluminescent substances which glow when struck by an electron beam in a cathode-ray tube.
Phosphorescence is a type of photoluminescence related to fluorescence. When exposed to light (radiation) of a shorter wavelength, a phosphorescent substance will glow, absorbing the light and reemitting it at a longer wavelength. Unlike fluorescence, a phosphorescent material does not immediately reemit the radiation it absorbs. Instead, a phosphorescent material absorbs some of the radiation energy and reemits it for a much longer time after the radiation source is removed.
A blacklight, also called a UV-A light, Wood's lamp, or ultraviolet light, is a lamp that emits long-wave (UV-A) ultraviolet light and very little visible light. One type of lamp has a violet filter material, either on the bulb or in a separate glass filter in the lamp housing, which blocks most visible light and allows through UV, so the lamp has a dim violet glow when operating. Blacklight lamps which have this filter have a lighting industry designation that includes the letters "BLB". This stands for "blacklight blue". A second type of lamp produces ultraviolet but does not have the filter material, so it produces more visible light and has a blue color when operating. These tubes are made for use in "bug zapper" insect traps, and are identified by the industry designation "BL". This stands for "blacklight".
In chemistry, chromism is a process that induces a change, often reversible, in the colors of compounds. In most cases, chromism is based on a change in the electron states of molecules, especially the π- or d-electron state, so this phenomenon is induced by various external stimuli which can alter the electron density of substances. It is known that there are many natural compounds that have chromism, and many artificial compounds with specific chromism have been synthesized to date. It is usually synonymous with chromotropism, the (reversible) change in color of a substance due to the physical and chemical properties of its ambient surrounding medium, such as temperature and pressure, light, solvent, and presence of ions and electrons.
Luminous paint is paint that emits visible light through fluorescence, phosphorescence, or radioluminescence.
Gum printing is a way of making photographic reproductions without the use of silver halides. The process uses salts of dichromate in common with a number of other related processes such as sun printing.
UV tattoos or blacklight tattoos are tattoos made with dyes that fluoresce visibly under a blacklight or other ultraviolet (UV) light source. Depending upon the tattoo ink used, an ultraviolet tattoo can be nearly invisible when illuminated only by light within the visible spectrum. Blacklight tattoo ink does not glow in the dark, but reacts to non-visible ultraviolet light, producing a visible glow by fluorescence.
Robert C. Switzer was an American inventor, businessman and environmentalist. Switzer was co-inventor of the first black light fluorescent paint along with his brother Joseph Switzer and the inventor of the Magnaglo process for nondestructive flaw-detection in machined parts. The brothers founded the Day-Glo Color Corp. in 1946 to develop and manufacture fluorescent paints, pigments and other products.
Super-LumiNova is a brand name under which strontium aluminate–based non-radioactive and nontoxic photoluminescent or afterglow pigments for illuminating markings on watch dials, hands and bezels, etc. in the dark are marketed. This technology offers up to ten times higher brightness than previous zinc sulfide–based materials.
A blacklight poster or black light poster is a poster printed with inks which fluoresce under a blacklight. The inks used contain phosphors which cause them to glow when exposed to ultraviolet light emitted from blacklights.
Lightfastness is a property of a colourant such as dye or pigment that describes its resistance to fading when exposed to light. Dyes and pigments are used for example for dyeing of fabrics, plastics or other materials and manufacturing paints or printing inks.
Tagging of postage stamps means that the stamps are printed on luminescent paper or with luminescent ink to facilitate automated mail processing. Both fluorescence and phosphorescence are used. The same stamp may have been printed with and without these luminescent features, the two varieties are referred to as tagged and untagged, respectively.
The Day-Glo Color Corp. is a privately held American paint and pigments manufacturer based in Cleveland, Ohio. It was founded in 1946 by brothers Joseph and Robert Switzer and is currently owned by RPM International. It specializes in fluorescent paint and pigments, such as those used in safety applications, artwork and signage. It invented black-light fluorescent and daylight fluorescent paints and nondestructive testing methods using fluorescent dyes.
The conservation and restoration of paintings is carried out by professional painting conservators. Paintings cover a wide range of various mediums, materials, and their supports. Painting types include fine art to decorative and functional objects spanning from acrylics, frescoes, and oil paint on various surfaces, egg tempera on panels and canvas, lacquer painting, water color and more. Knowing the materials of any given painting and its support allows for the proper restoration and conservation practices. All components of a painting will react to its environment differently, and impact the artwork as a whole. These material components along with collections care will determine the longevity of a painting. The first steps to conservation and restoration is preventive conservation followed by active restoration with the artist's intent in mind.
Paint mixing is the practice of mixing components or colors of paint to combine them into a working material and achieve a desired hue. The components that go into paint mixing depend on the function of the product sought to be produced. For example, a painter of portraits or scenery on a canvas may be seeking delicate hues and subtle gradiations, while the painter of a house may be more concerned with durability and consistency of colors in paints presented to customers, and the painter of a bridge or a ship may have the weatherability of the paint as their primary concern.