Invisible ink can be used to write secret messages, which are only visible with certain types of eyewear. This type of ink has been used for centuries to convey hidden messages, including by spies and secret lovers. It’s a great way to send information you don’t wish others to know, like passwords or phone numbers of roommates.
Many different substances can be used to create invisible ink. Some of them only appear when heated or exposed certain chemicals, while other require a specific light to reveal their message. A message written in lemon will appear on paper when heated. Some invisible inks can be seen under a UV or blacklight, while others are only visible with certain infrared cameras and lenses.
The longevity of invisible pens varies greatly depending on their composition and quality, as well as the way they are stored. Generally, it can last anywhere from a few days to several years. However, some types of invisible ink are only permanent when they are heat treated, while others will fade over time or if exposed to sunlight.
Can blue light glasses see invisible ink?
Blue light glasses are designed for filtering harmful ultraviolet (UV), and therefore they will not be able able to detect ink. Blue light glasses may be able to reveal invisible ink if it was designed to appear under UV light.