not really sure if this is the right forum but... 8)
I need ultraviolet ink (uv ink, blacklight ink, invisible ink ... bla bla). What is the chemical formula of this stuff? Is there any way to home-make/lab-make-produce it?
I know one chemical complex that works almost like this. It works only when it is wet (but water steam in air is usually adequate) and in normal light it looks like yellow, with little "blink" or "reflex". In ultraviolet it emite green-yellow light. It is called fluoresceine, checkout some chemical books.
Dissolve 200mG or greater quinine sulfate tablets (an anti-malarial agent available at many online drugstores) in water. Crush with six tablets per 50mL (around 2 ounces) water to start. Add a few drops of sulfuric acid (you can take a few out of a cell in a fully functional lead-acid car battery with an eyedropper if you do not have sulfuric available), test with your UV source as you add to see when additional acid does not intensify further. The ink dries to an invisible-in-sunlight state which shows up blue under UV.
And here is a source for low cost inks if you decide not to fool with it. (In the U.S.):
**broken link removed**
I don't have an answer to your second question, at least not yet.