Dyeing or placing inconspicuous signs on cards is a technique that allows cheaters to navigate the deck, deal and draw the necessary cards. There are a huge number of tricks used by dishonest players.
Cheaters can make a deck with hints in advance or arrange them during the game. The problem with the first option is that players may refuse to play the proposed deck, the second option is simply less accurate.
Most popular ways
One of the most famous and widespread methods is called "kotska". For cards marked in this way (usually aces and tens), the front side is processed in such a way that it becomes rough in one direction, and for the rest, the "shirt" is made rough. When shuffled, the cards stick together, allowing the cheater to guess with confidence which card he is holding.
Molten paraffin is often used for spotting. The corners of the map are lowered into it to different depths, which makes it possible to further distinguish them. As a result, the processed corners are easily felt with the fingers during shuffling.
One of the easiest spotting methods is the side dot. Notches or dots are made on the side edges of the cards, which are quite easily felt with sensitive fingers.
The next method of spotting also requires sensitive fingertips - on the surface of the card (usually in some corner), a simple sign of dots is placed with a needle, by which you can determine the value of the card. A person with rough and untrained fingers will simply not notice such an icon.
Some cheaters erase the glossy surface of the "back" of the card with a regular eraser. With the right lighting, they can distinguish such markings, which are almost invisible to the people around them.
Many dishonest players exploit an interesting property of factory paint. If you put a regular deck in a damp place for a while, gum arabic, which is found in most factory paints, softens and becomes quite sticky. When dealing cards, it is enough to press the deck firmly with the thumb of your left hand, simple cards without pictures slide easily and effortlessly with this method of dealing, but picture cards with an impressive shading area stick to the lower ones.
If the game started with a regular deck, the sharper tries to place the mark directly during the game. To do this, he draws lines with his fingernail at the edges of the card, after which he easily identifies it by touch during further distributions. Sharkers, who specialize in spotting decks as they play, have very thin skin on their fingers, which provides high sensitivity.