Marked playing cards here refers to the marking cards with luminous ink marks on the back for invisible ink reader to see.
Other marking cards strategies includes the bar code marked decks for poker scanner analyzer, IR marked cards for IR camera, invisible code marked cards for infrared glasses, physically making small markings on the back and so on.
We are mainly talking about using infrared contact lenses to detect luminous ink marked decks here.
The contact lenses have small purplish filters built into the lens. When you put the contact lenses in your eyes your vision is transformed into a purplish vision (like a black light) and you are able to read luminous "invisible" markings. The invisible ink marks can be applied to the back of red, blue or other color cards. The contact lenses read both which is an advantage over the glasses which can only read the back of red backed cards. The contact lenses are the most effective and discreet way to read the invisible markings. The contact lenses are made of the same material regular contact lenses are made out of.
Usually the size of the entire contact lens is 13mm-14 mm which is the standard size of a contact. There are a few different sizes for the lens filter. There are normally 9 mm, 6 mm and 4 mm standard lens filter sizes.
And for some special requirements, we can customize 7mm and 3mm lens filter.
