Have you ever thought of marking playing cards with invisible ink to see through by UV contact lenses by yourself? I can tell you if you have cards marking invisible ink and magic luminous ink pen, you can do that. Also, you can buy theses marked cards kit from GS marked cards poker devices Company online from China not from India.
Marking poker cards by hand at home is an art which needs skills. This magic luminous ink pen can mark invisible ink on the back of playing cards decks. You can mark letters or numbers that you can recognize easily. All kinds of your own marks is Okay. After the ink dry, you can wear marked playing cards glasses to detect invisible ink marks and we cannot see through luminous ink marks by our naked eyes.