Chapter 1
Ancient formulas that bound the written world
View / Create
Answer
Chapter 2
The chemical secrets of novel and invisible inks
View / Create
Answer
Chapter 3
Hermann Rorschach and the birth of the inkblot
View / Create
Answer
Chapter 4
The controversy and cultural legacy of inkblots
View / Create
Answer
YOUR GOAL
Master of Ink from scribes to inkblots
Ch 2 · The chemical secrets of novel and invisible inks
schopenhauer Revolutionary War Invisible Ink
Brush it on, brush it on, Now the secrets bloom!

schopenhauer Match historic inks and inkblots to discover how writing and psychology shaped our world.
Glossary
sympathetic ink (noun)
A substance used for writing that remains invisible until revealed by heat or a chemical reagent. During the American Revolutionary War, George Washington's spy ring used James Jay's chemical formula to send secrets.
A substance used for writing that remains invisible until revealed by heat or a chemical reagent. During the American Revolutionary War, George Washington's spy ring used James Jay's chemical formula to send secrets.
Quiz
What is the primary cause of iron gall ink's tendency to eat holes in historical documents over time?
Quiz
How does electronic ink (E Ink) conserve battery life compared to traditional LCD computer screens?
Quiz
Who invented the 'sympathetic stain' invisible ink used by George Washington's Culper Spy Ring?
Quiz
The warm, reddish-brown ink color known as 'sepia' was originally harvested from which marine animal?
Quiz
What natural forest object provides the tannic acid required to make traditional iron gall ink?
Quiz
Which metal sulfate is mixed with tannic acid to create the dark pigment in traditional iron gall ink?
Fun Fact
Oak galls: Iron gall ink was made using abnormal growths on oak trees called galls, which are triggered when a tiny wasp lays its eggs inside the tree's buds.
Quiz
In what year was the modern electronic ink (E Ink) technology invented at the Massachusetts Institute of Technology?
Quiz
What pigment gives cephalopod ink, such as that from cuttlefish, its dark brown or black color?

