There are several ways that cards can have markings on them to give cheaters or hustlers a competitive advantage when playing card tricks or gambling. The markings can be subtle, such as colouring or scratching parts of the deck’s back or tinting certain sections. Some types of marking are invisible to the naked eye and require special glasses to see but others can be detected by using a simple device known as the riffle test.
Traditionally the simplest way to Marked playing cards is to apply pre-prepared marks to a deck before it is used in game. There are many ways to do this, some of which require a high degree of skill. This is why hustlers and cheats often spend so much time practicing and honing their skills with these techniques.
This is a common method of marking a deck of playing cards. The ink used is usually a shade darker than the card stock. This technique can be used in many different ways, including block-outs where the design of the card is blocked out using ink that matches the card stock’s shade and cut-outs where white areas such as birds or flowers are scraped away with razors or other sharp tools.
These advanced card markings systems include luminous markers, which can be viewed with special contact lenses or sunglasses. These are more difficult to use for gamblers as they require additional manipulation skills to ensure the luminous ink cannot be seen by other players.
A newer method for marking cards is to use a chemical called “juice dust” to mark the cards on-the-fly. This is a variation of the daub technique that can be used to alter cards without the gamblers realizing it. The strength and visibility of the juice dust marks depend on the ability of the cheaters to read patterns on the back of cards.