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

In another, attributed to Aeneas the Tactician, a message hides dots of invisible ink over certain letters, which spell out the true message.

From Scientific American

Meanwhile, Nina has always lived as if in invisible ink.

From New York Times

Dasch's handkerchief held the names of the saboteurs' contacts in America, written in invisible ink.

From Literature

They were taught how to make more invisible ink using things like aspirin and Ex-Lax.

From Literature

Each match was actually a pen that wrote with invisible ink.

From Literature