The process of altering playing cards is known as card marking. This is a very effective cheating method as the marks are apparent only to the conspirator. After the marking process, the cards can be used for magic tricks on one hand, or for cheating in a variety of poker games, on the other. Usually the distinguishing mark or marks are done on the uniform back side of the playing cards, and in this way the effectiveness of the cheating is guaranteed. The easiest way to mark probably is called card bending. When using this method, the cheater marks the cards by crimping.
Card marking is often used to cheat when gambling or for card tricks, regardless of who shuffles and deals the cards. Sometimes additional manipulative skills are needed to steer the desired cards into the correct positions. No matter the effectiveness of the card marking, many casinos have adopted a method to prevent cheating. By punching holes through the middle of the cards they sell to tourists, the casinos are trying to protect the game tables, from cheaters who are slipping favorable cards into their hands when playing.
The history of marking playing cards
Actually the first marks on the playing cards were crimps, bends or even tiny bumps, called blisters that resemble the Braille script. With the appearing of the first designs on the back of the cards, the cheaters started to alter the designs by using various inks or pigments. Adding or removing lines or patterns on the back of the cards is the most common method, but there are many others as well, such as block-out work, cut-out work, scroll work, shade work, tint work.
With the development of science and technology, the marked-card techniques have enhanced very rapidly. As we have already said, there are a lot of ways for marking, but the most advanced are the shade techniques, which are the most deceptive and futuristic.
In brief we will present you the most used types of cards, marked with the shade technique:
Luminous marked cards - These cards can only be read by special contact lenses or gimmicked sunglasses. The original luminous systems use green inks to mark the back of red cards, and the lenses you should wear to detect the marks are red-colored.
The newest luminous technology is called Ultra-Luminous and it is far more effective than the original luminous systems. The Ultra-Luminous technology in fact is based on complicated chemical formulas and optical scientific principles, which makes almost impossible for marked cards to be detected.
Video-luminous marked cards – These are cards that differ from the usual luminous marked cards. The marks on the video luminous cards cannot be seen even if you wear the special filtered sunglasses. What you need here is a custom-designed electronics and filters, through which you can read the marks . But you cannot see the marks directly, the tip is that these are displayed on a monitor situated in another room to a partner of yours. That partner is the person who will communicate you the card value.
Usually these cards are not for cheating but for magic tricks. Most often are used by the poker houses in order to analyze a card game or to detect collusion. The unusual play is easily to find out, as it is enough just to play back the recorded images of the marked cards. The easiest way to suspect that collusion is taking place during the game, is to watch out the hands that the partners fold– when a player constantly have a good hand and his partner plays even better hand, this is a considered as a clear sign of cheating. And usually the poker house introduces such marked decks only when the suspected colluders are seated.
Have in mind that these marks cannot be seen with a naked eye, and even for the most experienced players is hard to detect such decks. So, it is almost impossible to understand when you are involved in a game with video-luminous marked cards.
Juice-marked cards – These are also commonly used. The signs are visible even to a naked eye, it is enough to have just a little practice and experience in readings such marks. You can also use the special sunglasses in order to detect the marks in an even easier way.
The biggest advantage of the luminous and juice marked cards is that the signs are visible even from across the table.
Now, let us tell you a few words about the different techniques for card marking.
Block-out work – This is a simple mark technique, as the ink color is the same as the back colour of the cards. The trick is that with the same ink are colored small white areas on the back of the cards. For example, there are narrower lines or even block out figures, as birds or flowers on the back design.
Cut-out work – Contrary to the block-out work where the lines are narrower, in the cut-out work some of the colored ares of the cards are scraped off, usually by a razor or anything else sharp enough. The result is that white figures are cutted off on the backs of the cards.
The disadvantages of these two traditional techniques is that the marks are too small, so the player can only read them close-up. Also they can be easily detected thanks to the gambler's riffle test. That is why the professionals prefer juice or luminous methods.
Tintwork or shade – The cards are marked by a tint solution. The back designs are those that determine the marking patterns.
Daub – This is a very interesting method as it occurs during the game. One of the players marks the deck of someone else with the help of a special paste. As stated above this happens during the game and in this way the need of using a pre-marked deck of cards is eliminated.
Juice dust – Another type of the daub technique, which is even better as the juice dust method doesn’t dull the finish of the cards. Again it occurs during the game, and one of the players is marking someone else's deck, so the normal deck turns out into an ad-hoc juiced deck. Another advantage is that this technique works on both paper and 100% plastic playing cards.