Invisible Ink

Invisible ink, also known as security ink, is a substance used for writing, which is invisible either on application or soon thereafter, and which later on can be made visible by some means. Invisible ink is one form of steganography, and it has been used in espionage. Other uses include anti-counterfeiting, property marking, hand stamping for readmission, fun children's games, and marking for the purpose of identification in manufacturing.

Read more about Invisible Ink:  Application and Use, Properties of An "ideal" Invisible Ink, Screening Letters For Secret Messages, Invisible Ink Types, Modern Relevance of Invisible Ink Messages, Digital Invisible Ink

Famous quotes containing the words invisible and/or ink:

    They threw off their clothes, and he gathered her to him, and found her, found the pure lambent reality of her for ever invisible flesh. Quenched, inhuman, his fingers upon her unrevealed nudity were the fingers of silence upon silence, the body of mysterious night upon the body of mysterious night, the night masculine and feminine, never to be seen with the eye, or known with the mind, only known as a palpable revelation of living otherness.
    —D.H. (David Herbert)

    Who does not see that I have taken a road along which I shall go, without stopping and without effort, as long as there is ink and paper in the world? I cannot keep a record of my life by my actions; fortune places them too low. I keep it by my thoughts.
    Michel de Montaigne (1533–1592)