Marked cards with sunglasses are a method of cheating poker. It allows players to see invisible markings in playing cards. These markings can help identify the suit and value of a card, along with other information like an opponent’s cards.
Unlike other types of poker cheating, marked cards with glasses are relatively rare and require a significant level of skill to perform. It is a very discreet way to cheat in a poker game, but it can be difficult for others to notice.
These cards are marked with a light reflective chemical daub, paint or other substance that reacts only to certain wavelengths of visible light. This allows cheaters to bounce an invisible light source from the back of a card and see the markings with contact lenses or special glasses.
The chemical dabs are often colored with a dark-green or black pigment. They are usually placed on the back of a deck of cards and can be viewed using contact lenses or special sunglasses that contain a “built-in” filter.
Shade technology can also be used to mark cards. Some card cheats add a lighter or darker shade in certain areas. This shade can be applied by hand (brush), or mechanically using an aerobrush and templates to precisely position the marks.
These markings are often made with luminous ink. But there are other ways to make them. Two common options are NU – CONcept paste (TM) and Juice DustTM. However, other types of inks may also be used.
Another option is to use special shades that can be painted or brushed onto the card’s front. This material is primarily composed of pure grain alcohol with a tiny amount of the most permanent, durable, and fade-proof inks or dyes. This is sometimes called “two-way shade” and is nearly colorless, but it does provide enough tint to gray the white areas.
Some people use a combination or luminous and not-luminous daubs to make their own markings. These can be applied to any type of card and are incredibly effective.
There are several ways to identify these markings. These include looking through a dark filter, looking through an ultraviolet light, and performing the “riffle” test. All of these techniques will help to identify the markings but they are not foolproof and are a bit tricky to learn.
These markings can be easily read using a pair red filter glasses. This will require a little practice to master but once you do it can be a very fun way to reveal a hidden numerical value and suit on a card.
You can also buy special glasses with a built-in filter to allow you to use luminous ink. These aren’t as expensive and can be a good option for people who want to secretly read marked papers.