invisible ink

[ in-viz-uh-buhl ingk ]

noun

1. a fluid for producing writing that is invisible until brought out by heat, chemicals, etc.

invisible ink

noun

1. a liquid used for writing that does not become visible until it has been treated with chemicals, heat, ultraviolet light, etc

Word History and Origins

Origin of invisible ink¹

First recorded in 1675–85

Example Sentences

Last two words are written in invisible ink but can be easily discerned if Australian law books are held over scented candles.

From The Daily Beast

He communicated invisible ink on postcards, and a special code of microdots.

From The Daily Beast

Invisible ink makes an appearance in the complaint as does Morse Code, which, of course, is pretty uncrackable.

From The Daily Beast

We always write our most secret doings in invisible ink, made of lemon juice, so that nobody can read about them.

From Project Gutenberg

Dip the roses in the red invisible ink, the jonquilles in the yellow, the pinks in the violet, and the leaves in the green ink.

From Project Gutenberg

Here for some reason the invisible ink answered less reluctantly to the warmth of the blue flames' invitation.

From Project Gutenberg

Our censor chaps at home have got to be quite expert at reading letters, invisible ink and all that sort of thing.

From Project Gutenberg

By writing in newspapers, sometimes with invisible ink or by enclosing accounts or letters in them.

From Project Gutenberg