What is an invisible ink?

Invisible ink is a fluid used to write hidden messages that do not appear unless it is revealed by the exposing process. Invisible inks can be classified into three main categories: those that are revealed by heat, those exposed by chemical reactions, and those visible in ultraviolet light. Some ordinary household inks are diluted fruit juices, vinegar and laundry detergents that can be applied with a brush, a special invisible ink pen or even a toothpick. Historically used during the war of government and insurgents, Ink's Peace applications include children's invisible ink books and real estate brands. The chemical processes of invisible inks are well known, so there are a number of detection methods. When it dries ink, it will be invisible to the mere eye, but if the paper is held up to an anchor heat source, such as a bulb, radiator or iron, the writing of lemon juice will brown in front of the rest of the paper and expose a message. Will also be a fungusT many other slightly acidic liquids such as apple juice, white wine, cola and even urine.

Spings is more likely to use invisible inks that are developed by a chemical process because they are safer and heavier to detect. During the Cold War, the German secret police used Cero Oxalate to write hidden messages and used the solution of manganese sulphate, hydrogen peroxide and other chemicals to reveal texts. The United States Government maintained its formula used during the classified First World War. Similar chemical recipes are used for children's entertainment, where hidden texts are printed in an invisible ink book and the invisible ink pen is used to give tracks and detect the end of the book. Some of the well -known chemical ink and dkombination Eveloper are vinegar and red cabbage, as well as corn starch and iodine, both diluted in the water.

invisible inks that can be detected at VThe ultraviolet or black lights have many modern applications. Using a special brand, the invisible ink is applied to money or valuable goods so that in the case of theft, the article can be identified by pawns or police and can be returned to the authorized owner. Many nightclubs use invisible inks to take the hands of the patrons for return and some tattoos use an ink that is visible only in black light. Copyrights are sometimes printed on documents with ink sensitive in the ultraviolet, which prevents the missing of the photocopy for the originals. Desperate prisoners with limited resources can write hidden messages in the outside world using body fluids that contain phosphors that are detectable by ultraviolet lights.

Several reliable detection methods caused invisible inks mostly part of history. Depending on the ink, the communication odors and the scratches of the pen may distribute the use of invisible inks. When it is suspectedThe suspicion of invisible writing that is sensitive to ultraviolet light or heat can be easily detected. Chemically reactive inks is more difficult to find out, but Iodine pairs indicate whether paper fibers have been disturbed by a pen.