It’s a common pastime to write secret messages in invisible pen, whether it’s just for fun or as a prank on friends. What if you were able to decipher the messages with a pair of special glasses? In this Wonder of the Day video, we show you how these magic invisible ink lenses are made and used.
Invisible ink is liquid that can be seen under certain conditions. It usually becomes visible when exposed to light. It is commonly used to mark cards in a poker game or other card games. However, it can also be used for other surfaces. Luminous reader invisible ink marked cards are a great way to cheat at many types of casino games, including Omaha Hi-Low, blackjack, Baccarat and low ball.
The most common form of invisible ink is heat-activated. It can be made from a variety of organic liquids such as lemon, vinegar, or clear soda. It can also be made using other chemicals that change colour when heated, like those found in the saliva of a Cranberry or the blood of corpses. It can also be sprayed directly onto paper, dried and then rubbed down with iodine.
You can reveal most of these heat-activated inks by placing paper under a source of light, such as an 100-watt bulb, or a hairdryer. The important thing is to take care not to set the paper on fire. For this reason, it is recommended to lay the paper on a heatproof plastic sheet.
Some invisible inks require a specific chemical substance or chemical to reveal the message. For example, soapy or warm water can be applied to reveal a message written in lemon or iodine to reveal messages on a smear. These types are often called sympathetic inks.
Invisible ink has been around for many years. It’s particularly useful for communicating with people who might otherwise be unable to see what you’re writing, such as the blind or those who are hard of hearing. It can also add a little extra excitement to your everyday text messages, breaking up the monotony of an endless stream of social media notifications or workplace emails.