invisible writing ink

invisible writing ink

[in′viz·ə·bəl ′wrīd·iŋ ‚iŋk]
(graphic arts)
Ink that remains invisible until the color is brought out by the application of heat or chemical; made with sal ammoniac or salts of metals.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
* The photographic detection of invisible writing inks [5];