Marked cards for sale are playing cards that have secret markings on the backs or sides to help magicians or poker cheaters identify the suit or value of a card quickly and accurately. These markings can be read in various ways, including by using invisible ink, scanner cameras or glasses. Some marked decks use special chemicals to add luminous marks to the cards that can be read by light-sensitive devices, such as infrared contact lenses or gambling sunglasses. Others use tint solutions that are only visible to a trained eye.
In the past, people have used a variety of techniques to mark cards in order to increase their chances of winning card games and magic performances. Some of these were fairly sophisticated and involved bending the cards or altering their design. Other marks were less subtle, such as crimps and tiny pinprick bumps known as “blisters” that resemble the Braille script. In recent years, players have begun to mark their playing cards using a variety inks, pigments, and scratches. These methods were dangerous, and they often required a trusted friend to read the markings.
A recent innovation was the creation a deck of playing cards that could be marked in real time, even as they were being played. This process is known as juice-marking, and the markings are only visible to a person who knows how to spot them. The mark is usually a small coloration or tint on the card, and it may vary depending upon the back design of the cards being marked.
Other methods of marking playing cards include block-out, scroll, shade, or tint. These methods are more complicated and require a skilled partner who can read the markings. However, they allow for subtler marks, such as coloring a white bird into the back design of the card.
A special paste can also be used to mark a deck. It can be applied immediately or even while playing the cards. This method is called daub and can be very effective, although it does have some limitations. It can be difficult to apply the daub properly and it can leave a residue on the cards which can make them unplayable.
A final type of marked deck is one that uses a video-luminous marking system to mark the cards. This is a more expensive and advanced version of marked cards. It offers several advantages over other types. One of the advantages is that a person can read the marks by wearing a pair custom-designed glasses with filters. This is much more convenient than filtered sunglass. Cards can be recorded, and then played back, which is useful to analyze the outcome of the game or look for signs of collusion. A video-luminous marked deck can be used in a variety of games and magic acts.