Invisible ink is an interesting way to hide messages that can only be revealed under certain conditions. These conditions include a chemical reaction, heat, and viewing under ultraviolet light. There are many ways of making invisible ink. Some include using soapy water or laundry detergents that contain brighteners.
The most common inks that are invisible are organic fluids, which change color upon heating. These types of invisible inks can become visible by heating the papers with an iron or hair dryer or by exposing them to a light bulb 100 watts. Some inks are also made of non-organic materials that change color when exposed to acid, such as methyl ethyl ketone and nitrocellulose.
To decode an invisible message, the person who wrote it must be able to find the right chemicals to react with the ink. Signs of this type are pen scratches or irregularities in the paper. These telltales alert a censor that a hidden message is present.
The use of clear sunglasses that can read marked cards is a great way to see invisible ink marks. These sunglasses look like normal sunglasses so no one will suspect that you’re using them to cheat at poker games. These sunglasses can be used in any setting, so some people like to use them when they play with their friends at home.