Secret messages require invisible ink ...

[cmeisenzahl]

 

Invisible Ink

"Although it looks pink in the bottle, this amazing ink goes on to paper wonderfully clear and invisible: it turns blue when the paper is held over a light bulb or other gentle heat source, and then disappears again as the paper cools.

 

Invisible Ink is water-based, and comes in a 1-ounce bottle. Please note the ink is suited for nibs and glass and quill pens, and cannot be used in fountain pens."

http://lshop.stores.yahoo.net/inkinvisible.html

[NeoTiger]

That's interesting. Easier than using a UV light for the Noodler's Blue Ghost.

 

However the Blue Ghost can be used in a fountain pen.

[QM2]

 

You know, you can also use milk for that. If you write with milk, it will dry clear on paper but will turn brown once the writing is held under a light-bulb. Communist revolutionaries used to do this in the 1900's-1920's.

 

QM2

[mgeorge]

You know, you can also use milk for that. If you write with milk, it will dry clear on paper but will turn brown once the writing is held under a light-bulb. Communist revolutionaries used to do this in the 1900's-1920's.

 

QM2

 

But I don't think the milk will disappear again when it cools, will it?

[Lloyd]

...but will turn brown once the writing is held under a light-bulb

or chocolate syrup is added to the milk. :ltcapd:

 

[Penache]

Writing secret notes in lemon juice was another method. You could only read it after heating the note.

[BillTheEditor]

As I recall, the type of invisible ink Chris wrote about is made by dissolving cobalt chloride in water. The writing, unfortunately, is not waterproof. If the paper gets wet, the message "disappears" permanently. The same shortcoming applies to writing in milk or in lemon juice. The advantage of the Blue Ghost ink is that it is waterproof and, yes, bulletproof -- the paper can turn to mush but the message will still be visible.

[QM2]

 

That settles it: Noodler's is better than milk. I've always suspected it

 

The same shortcoming applies to writing in milk or in lemon juice. The advantage of the Blue Ghost ink is that it is waterproof and, yes, bulletproof -- the paper can turn to mush but the message will still be visible.

 

 

mgeorge: No, you're right -- milk won't disappear again after cooling. I think they used to eat the paper at that point...

 

QM2

[Chris_PA]

That settles it: Noodler's is better than milk. I've always suspected it

 

The same shortcoming applies to writing in milk or in lemon juice. The advantage of the Blue Ghost ink is that it is waterproof and, yes, bulletproof -- the paper can turn to mush but the message will still be visible.

 

 

mgeorge: No, you're right -- milk won't disappear again after cooling. I think they used to eat the paper at that point...

 

QM2

 

Another reason is that the milk might be a little putrid after a week or so in your pen (out of refridgeration)

[BillTheEditor]

That settles it: Noodler's is better than milk. I've always suspected it

 

mgeorge: No, you're right -- milk won't disappear again after cooling. I think they used to eat the paper at that point...

Since it was the nineteen-oughts and teens when the Revolutionaries were communicating with cow juice cryptography, they were probably using a candle flame or an oil lamp to provide the heat that made the writing visible. No need to eat the message, just let it burn. Although, in those days, what with famine, starvation, and hunger being the order of the day, maybe those messages were an important source of nutrition. "Comrade! Here is a new manifesto from the Central Committee, written invisibly with milk on this letter." "Excellent, tovarich! We can have it with this crust of bread and some home-made vodka!"

 

(For the humor-impaired: that was a joke. I actually think the old Bolsheviks would have enjoyed it.)

[Tricia]

Just for the sake of completeness, there's also an invisible UV ink for the Fisher Space Pen. Neat idea, but I've always thought the pressure of the ball point would leave its own evidence. A nice wet-writing fountain pen with Blue Ghost wouldn't.

 

 

[guitarman19853]

I intend to buy a bottle of blue ghost soon. Especially since now it's gone up to a 3 oz bottle... Not that I'll ever use 3 oz, but it was the 1 oz size that was just one too many reasons not to buy it before.