The NTP marked decks with the special big marks are loved by our customers, especially those who need to see the marked cards in a little long distance. Because the big marks is big and clear enough for the marked cards lenses. As you can see in the picture, the marks have its own sign for suits as well as numbers in the middle of the back.
Generally speaking, the number with no sign stands for SPADE.
The number with a horizontal line stands for HEART (it's heart 8 in the picture).
The number with a circle dot stands for CLUB.
And the number with a vertical line stands for DIAMOND (that in the picture is diamond Q).