How do you read invisible ink

More and more people, especially poker players and magicians, use invisible ink to mark playing cards or write some invisible info on paper. How do you read invisible ink,  if you want to read these hidden markings and info?

There are several ways to read invisible ink markings

firstly, marked cards contact lenses. If you want to see the invisible ink markings on the back of poker cards, luminous contact lenses is the best choice, and the second choice is luminous sunglasses. Why marked cards contact lenses is better than luminous sunglasses? That's because no one will notice you wear contact lenses, with more secret.

Second way is using IR poker camera or just infrared filter. Infrared filter is basically for reading private info on paper, it's cheap and convenient.

Barcode poker deck scanner is the third way to read invisible ink. This invisible markings are special that they marked on the four edges of playing cards. Poker scanner camera and poker analyzer will help you scan and analyzer the barcode invisible ink markings.