When magician shows the playing poker cards to the audience, other magician would know that the cards is acctually marked with invisible ink or it is marked cards directly from the factory.
If you are real fun of the those magic cards poker, you can check who is the marked cards pathfinder, you will the pathfinder has no insteresting in the poker game, but just the sicence reserch and devolop, the juice ink was just invent by fortuity.
As now the invisible juice cards is revealed, you may want to know how to mark cards with an invisible luminous pen. If that is diffcult?
The answear is yes, cause as the marked playing cards usually divided into 3 types, the marked cards for contact lenses to read, the barcode deck for poker scanning system, and the infrared juice cards for the infrared camera.
If you write letter you will know, each people's writing habbit is not the same, so the juice flow out the invisible ink marker pen, the trace of the ink is not the same. It is too hard to control by hand when you use the ink marker. So if you really want the good quality cards, it is better to use the marked cards printer machine to make the mark. In this way, it can make sure the invisible ink mark is safe and invisible by naked eyes.
People will also ask what is the different of the invisible ink marker with uv light and invisible ink marker with IR light, acctually, you can tell the different from the IR and UV, UV means the mark can be checked under the UV light, just like the cash checker. And the IR ink mark be used for the IR poker camera.