Invisible Writing/Chemical Magic - Help Needed

[Guest]

Well, I made a mistake. I took Dunninger at his word. In his Monument to Magic, in a small blurb, Dunninger states you can paint a solution of Niter onto paper and when it invisibly dries, cause the writing to turn brown by putting a hot matchhead to the words.

Unfortunately, after I wrote a routine into my television show using this, I tried it. This doesn't work. Not only does it not work, it spectacularly does not work. I've certainly learned a lesson here (don't script until trying) but I need something that does work now.

Anyone have suggestions (besides lemon juice) on how to make invisible writing appear on paper when flame/heat is applied?

Thanks

[Guest]

I recall from many years ago using milk. I may have my wires crossed but I remember lemon and also that milk can be used, what the heck, try it.
Steve V

[Guest]

Mike - if this is truly for TV and you're looking more for a 'special effect' than trying to fool someone... try using a sheet of 24# white paper. Use flash string attached underneath the paper in the reverse of the image you are reproducing. When the string fires. it should scorch the image through to the front. I haven't tried this, but I'm sure it could be made to work, given a little experimentation.

If you're going to visibly apply heat to the paper (such as an iron) milk works as well as lemon juice. Hope it helps! --Asrah

[Bill Mullins]

Any liquid with sugar should work (soft drink, colas, fruit juices). You have to get the paper hot enough to caramelize the sugar, but not hot enough ignite the paper (451 degrees Fahrenheit, according to Ray Bradbury).

[Guest]

Good, old fashioned lemon juice (or vinegar) will also work. When the writing dries, it is virtually invisible. Holding the paper to a heat source, such as a 60 watt bulb, brings out the text in a dark brown color.

I'm sure that a microwave will speed up the process.

A good primer on secret writing methods is "Codes and Secret Writing" by Herbert S. Zim. I remember asking for it as a birthday present when I was a kid.