Can you see invisible ink using glasses?
Invisible ink can be revealed with certain types of heat or light. It is usually made from organic liquids like water, ethanol or propylene. These liquids are then mixed with acid-forming chemical such as thymolphthalein and methyl ethyl ketone. When the ink is heated (by ironing or holding it above a 100-watt light bulb), the thymolphthalein molecule condenses and the writing appears in white letters. This type of ink is used by printers for recording the serial number and printing date on their paper prints.
The most common way to reveal invisible ink is to use a UV light. This type of light can be found in most hardware shops and is used to make invisible pens visible again. Ink can also appear under a normal light bulb or a blacklight.
Some people wear invisible-ink clear glasses to see marked poker cards. These sunglasses have built-in red filters that can detect luminous invisible marks on the backs of marked cards. This helps to improve the chances of winning a game of poker by making it easier for players to identify the marks. Moreover, these invisible ink clear glasses are not only safe to wear but also look quite normal. They can be used in any environment, and are ideal for poker games.