There's a certain kind of damage which I feel is unintentional. Below is a picture from MY setup (not pfapfap). The marks are very hard to see, and is most visible from the card face as opposed to the back.
This happens when you place the cards perpendicular to you so the cards we a wide rectangle left-to-right, and squeeze the top corner to see your cards, a method I've been guilty of on the past, but try to avoid this as much as I can. I've seen this on both my Modiano and Copag setups.
