Ink, Invisible

Ultimate Equipment Guide II

Author Greg Lynch, J. C. Alvarez
Publisher Mongoose Publishing
Publish date 2005

For an untold number of years, the very existence of invisible ink was a secret carefully kept by the sages, scholars and loremasters of the immense Library of Truth’s Flame, one of the greatest depositories of knowledge and learning in the world’s history. The library was destroyed, burned to the ground by a conquering army, and the secret of crafting this ink was one of the few bits of knowledge that escaped the destruction. A young apprentice, having escaped with nothing more than the clothes on his back, sold the secret of making invisible ink when he had no other option to turn to in order to keep body and soul together. He was robbed and murdered several days later.

Invisible ink is not exactly what it sounds like, though it is very close. So long as the ink remains in a stoppered jar or phial, it looks like any normal black ink. However, after half an hour of continuous exposure to air, it becomes completely transparent, utterly invisible to the naked eye. As the ink is not magically invisible, it cannot even be seen with a see invisibility spell, though true seeing will certainly reveal it. Once the ink has become invisible, it will forever remain that way, unless the page upon which it is written is dusted with a specially-prepared alchemical powder.

As the means of revealing a page written in invisible ink has become well-known in the years since the starving apprentice sold the secrets of making the ink, those who continue to make use of invisible ink usually take extra precautions. The most common of these is to conceal the pages of invisible ink within a sheaf of truly blank pages.

Ink, Invisible (1 oz. phial and one packet of revealing powder): 20 gp

Source Adventurer’s Armory

Messages written with invisible ink only become visible under specific circumstances. Revealing the secret message with the proper triggering agent is a full-round action per page of text.

• Simple: Create Craft (alchemy) DC 15; This ink is keyed to a single, fairly common trigger, such heat or vinegar. A successful DC 20 Craft (alchemy) check takes 1 hour and reveals the message without the proper trigger.
• Average: Create Craft (alchemy) DC 20; This ink is keyed to either two common triggers or one uncommon trigger, such as blood or acid. A successful DC 25 Craft (alchemy) check takes 1 hour and reveals the message without the proper trigger.
• Good: Create Craft (alchemy) DC 20; This ink is keyed to either two uncommon triggers or one rare trigger, such as a specific vintage of wine or a specific kind of monster’s
  blood. A successful DC 30 Craft (alchemy) check takes 1 hour and reveals the message without the proper trigger.
• Superior: Create Craft (alchemy) DC 25; This ink is keyed to either two rare triggers or one unique trigger, such as the blood of a specific person. A successful DC 35 Craft
  (alchemy) check takes 1 hour and reveals the message without the proper trigger.