[jack]

You guys remember those magic pens, the ones that changed colour when you drew over another pens line?

I'm looking for a printing process that would allow for the same reaction, anyone ever heard of anything like this?


For example If there was a seemingly blank sheet of paper, but when written upon the pens ink would react with certain areas forming images or text.


Is that too far out or anyone know if it could work? I'll speak to the printers, but any advice would be appreaciated.