There’s not just one ink formula. But I can tell you this much: Most of our inks are based on water or alcohol. But since we have literally thousands of formulas by now, I can’t offer much by way of generalizations.
In that case, we hope you’ll answer this question, at least: Is there really any such thing as invisible ink? And if so, how does it work?
Oh, most definitely! But the formula is top secret, as you might expect. While MI6 and the CIA still use fountain pens with their invisible inks, we have gone beyond that to develop printer’s inks with the same properties as part of our product range. The key there is that the ink can only be seen under UV or black light, since it is the only type of light that interacts with the pigments. This effect is used for things like ensuring the authenticity of documents. It’s almost like an invisible watermark. But it doesn’t last forever, so invisible printer’s ink isn’t suitable as long-term proof of authenticity. Other properties can be used for that. For example, we can give an ink radiological properties that allow it to be read via X-ray radiation, CT scanning, magnetic resonance imaging (MRI), or mechanical waves (ultrasound).