|There are many types of invisible ink.
Before we talk about where to get them or how to make them, it’s
important to know how to use them. If you write on a blank piece of paper
with invisible ink, you might forget why you are carrying that blank paper
around. Or somebody who suspects you have a secret will suspect that you
wrote on it in invisible ink. Why else would you carry around a blank
piece of paper?
A note pad is normal looking.
But not a blank one. You should write in your notepad. Write as if you
have no secrets. Write neatly, in large letters with space between the
lines. Then you can use the space between the lines later when you write
secrets in invisible ink.
A letter also looks normal. In
fact, if you let your girl friends know you are carrying a love letter,
they’ll be eager to read it, but they won’t suspect the love letter
also has a secret hidden message. And even if they read it, they’ll put
it back because they won’t want you to know they’ve been snooping.
Letters are also a useful way
to send messages to other agents. You can use the neat large writing
technique to send a normal letter and put your secret message between the
lines in invisible ink. If you are really intent on keeping the message
secret, you can also write the secret message in code.
Cell Phones allow for short
text messages. You and your agent can agree on code words to convey preset
messages. For example, if you are following someone, you can tell your
agent that you have found the suspect at the ice cream shop, or the mall,
or the library by sending an agreed upon word such as hat for ice cream
shop, fly for mall or pig for library.
Email can be encrypted. Or you
can have every other line be your true message, or every other word. You
can find many systems of hiding messages in letters at your library. All
of them can be applied to email. You can even send a series of links to
web pages. The first word on the first page can be the first word of your
letter. The second word on the second page can be the second word, and so
forth. Play around with this and come up with something original that only
you and your agents will know.
Here's a website with codes and other secret messages that
were sent over 200 years ago: Spy
Letters of the American Revolution The methods are still workable
And don’t forget to destroy secret messages as soon as
you have memorized them or done what they described. Spies don’t keep
records for others to find. A spy’s work is only judged by results –
not by a paper trail. And a paper trail can tip others off to your secret
An easy invisible ink is lemon juice. You can write with
it, and then you can reveal the writing by briefly placing your paper on a
light bulb. You can buy inks that are visible under ultraviolet light, and
you can buy a UV bulb at most hardware stores. Some more sophisticated
inks require special solutions to make them visible.