Watermark/Invisible Ink?

[DJ STANKDADDY]

I'm looking for 'watermark' and or invisible ink. That only shows up when held to a light source. For example say I printed trees on a white sheet of paper, and when I held said image up to a light source, a sun would appear, or an image that was otherwise invisible. I've looked around and also herd things about photo emulsion (have no idea how this relates to watermarks), screenprinting, and stamps with regards to watermarks. Any and all help/suggestions appreciated.

 

[moderngurl]

How about using lemon juice? Urine can also be used as an invisible ink. LOL

 

[Laser Tek]

Hello DJ SRANKDADDY:

I'm sure you're not referring to any printer-related stuff because what you're looking for doesn't exist yet in the market.
Anyway, here's a list for heat-activated invisible ink:

•any acidic fruit juice (e.g., lemon, apple, or orange juice)
•onion juice
•baking soda (sodium bicarbonate)
•vinegar
•white wine
•dilute cola
•diluted honey
•milk
•soapy water
•sucrose (table sugar) solution
•urine

-I'm serious with the last one anyway.