An Ultraviolet (UV) marker is a invisible ink pen whose marks are fluorescent but transparent: the marks can be seen only under an ultraviolet light. They are commonly used in security situations to identify belongings or to protect from the copying of banknotes and playing cards. UV pens can now be bought at some stationery shops to security mark items of high value in case of theft.
Materials used to make UV markers
The body of a UV marker is made by plastic similar to a normal marker. The ink used in UV markers has been made from various things in the past such as lemon juice, vinegar, diluted blood or even urine.[2] Modern UV-invisible ink is mainly made by a fluorescent derived from things in nature that glow when exposed to an ultraviolet light. The main components include dilute laundry detergent, body fluids, tonic water and vitamin-12 dissolved in vinegar. There are different types of UV-invisible ink: opaque, semi-opaque and translucent. All of the three contain acrylic monomers which contain a diluent and a photoinitiator to participate in the curing reaction and to respond to UV radiation. Photoinitiators is a very important element for making the ink as it is the substance that absorbs the UV mission of a UV light, which enable the marker to work.
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