I was shown by a friend an application of the frixion pen to make a signature disappear.

If I had a pen that did the opposite (invisible ink that appears with heat) I will be able to make a picture/signature change!

But I don't like the color of lemon juice.

Is there an invisible ink that turns black when heated?

Thanks, Tim.

You can do what you ask with a Frixion pen or marker. Use it in conjunction with a regular pen. Think about it.

Jim

Dear J-Mac,

I have given it a lot of thought, But I cannot figure out a way.
Maybe using frixion on black paper I could make a signature appear.
But for a signature to morph to another I would need some kind of ink that appears with heat.
I was thinking about using B*rn N*tice, but does this work with paper?

Thanks, Tim.

Tim,

Methinks you are missing my point. I sent you a PM.

:)

Jim

Also looking for something similar.
any tips would be appreciated.

Cheers
Durgy

In the book stone, friction, fire , I think that's what its called, I am in hospital at the moment so can't check, there are many uses for these pens described, well worth a look

You can write with a weak solution of cobalt chloride on off-white parchment. It is not hard to find (try eBay) and is not dangerous to work with. When heat is applied, the writing will not appear in black but a very nice blue.

Christopher

Get well,George . I hope it is a short stay.