What forest object provides tannic acid for iron gall ink?
Chapter 1

Ancient formulas that bound the written world

Chapter 2

The chemical secrets of novel and invisible inks

Chapter 3

Hermann Rorschach and the birth of the inkblot

Chapter 4

The controversy and cultural legacy of inkblots

YOUR GOAL

Master of Ink from scribes to inkblots

Ch 2 · The chemical secrets of novel and invisible inks
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schopenhauer Revolutionary War Invisible Ink

Brush it on, brush it on, Now the secrets bloom!

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schopenhauer Electronic ink and the digital paper revolution

Aug 26

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Ink & Think
BETA

schopenhauer Match historic inks and inkblots to discover how writing and psychology shaped our world.

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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.

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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.

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Gossip

Would you prefer reading books on digital e-ink or physical paper?

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Quiz

What is the primary cause of iron gall ink's tendency to eat holes in historical documents over time?

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Quiz

How does electronic ink (E Ink) conserve battery life compared to traditional LCD computer screens?

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Quiz

Who invented the 'sympathetic stain' invisible ink used by George Washington's Culper Spy Ring?

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Quiz

The warm, reddish-brown ink color known as 'sepia' was originally harvested from which marine animal?

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Quiz

What natural forest object provides the tannic acid required to make traditional iron gall ink?

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Quiz

Which metal sulfate is mixed with tannic acid to create the dark pigment in traditional iron gall ink?

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Quiz

In what year was the modern electronic ink (E Ink) technology invented at the Massachusetts Institute of Technology?

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Quiz

What pigment gives cephalopod ink, such as that from cuttlefish, its dark brown or black color?

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