May be you have used the Copag 1546, how do you think about it? This is a Copag Bridge Size Jumbo Index 1546 Playing Cards made of 100% PVC plastic, and these cards will last for years outlasting paper cards up to 500 times. Bridge sized (2.25 x 3.5 inches). Completely washable, so you don't need to worry about soiled cards. If you have soiled the cards, a quick wipe with a damp washcloth, then poker will dry and you have solved. Includes durable and solid hard plastic storage case.

It also a good choice to mark as a invisible ink playing cards, here are some information as followed:

Brand: Copag

Material: 100% plastic

Model: narrow jumbo Index, narrow standard index, wide jumbo index, wide standard index, 2 deck set.

Cards: the decks contain 52 cards and 2 jokers.

Color: red and blue, green and burgundy, orange and brown, gold and black, purple and grey

As for the marks on contact lenses marked cards, we usually marked as a big marks in the middle. It also can be marked cards as barcode marked cards for poker analyzer system.