A marked deck is a set that has been altered to give the cheater an advantage. There are several different types of markings that can be used on a card, but they all work in a similar manner. Basically, a mark is made on the card that is invisible to anyone who is not wearing special glasses or viewing it under certain lighting conditions. Some marks require more sophisticated equipment than others, yet all are designed to give a cheater a unfair advantage over their opponents.
While there are several ways to mark a set of cards, the most common is to use luminous or liquid markers. This method uses a special chemical to make the marks visible for the cheater. It is also relatively easy to use and is inexpensive. This type of marking has a downside in that it must be read up close and cannot be seen across a table.
Another method of marking a deck is to use a marker that is invisible to the naked eye but can be read by a specially-tinted lens. These lenses are sometimes called “infrared contact lenses” or “luminous glasses”. They are designed to block out the ultraviolet and the infrared light frequency that is normally seen by the eye. They are available from a number of online vendors and can be purchased for a reasonable price.
Luminous marker contacts are usually clear and look like regular sunglasses. They can be worn for an extended period of time without changing the color of your eyes or causing any other side effects. Infrared lenses are more complicated but can still be worn for a long time.
With the advancement of technology, it is more common to mark cards with chemicals which can be read through a special contact lens or glasses. This kind of technology is based on the fact that cards can be printed with invisible ink that, when reflected off of the surface of the card, creates a difference in light dispersion between blue and red components of light. Invisible ink marks are a lighter or darker shade gray when viewed through special glasses or lenses.
These invisible marks can be created using “shade” technology. The backs are marked with lighter or darker inks in certain areas. These markings are normally invisible to the naked eye. However, they can be seen with contact lenses or special sunglasses that have a yellow filter.
To spot card marking techniques, players can also riffle cards carefully and look for any marks. However, this method is not foolproof, and it won’t detect all types of marking. For example, a deck of cards that have been marked with luminous ink or other special markings will not be detected by this technique.