There are many professional poker players searching for the anti-poker cheating device. Most of them need a polarized ink pen to mark invisible ink marks on the back of marked playing cards. Here we can provide you with many invisible ink pens. This invisible ink pen can help you save time and money as you can mark the luminous ink according to your requirement. And these infrared luminous ink marks cannot be seen by someone who hasn’t wear our magic contact lenses or infrared glasses. If you don’t know how to mark the marks on back of poker cards, you can mail your poker cards to us. We will mark your poker cards with our professional techniques and invisible ink pen.