Thank you so much for the talcum powder suggestion! I will try that.
I feel the same as you do. The worn parts of the image don't bother me, cosmetically. I am mostly looking for a way to make sure that I'm not making the worn spots bigger each time I shuffle. I even had the idea to maybe kind of gild the cards in spots? I really do like the deck, and would want to keep it, but it's not my main deck so I probably won't buy a replacement unless I find a good deal.
Hi CMcQueen, I know that there are some varnishes that are used to block images or decoupage work, and these come in matte, satiny of shiny, so I suppose you could find one to match the cards. It could protect the damaged parts, so that it does no chip further. ModPodge does some, and there are other brands, you can look them up in craftstores.
BUT I would be very careful before applying some on my cards.
First, really try it first on a random piece of paper and cardboard. I have used some of these varnishes in the past, only to find that they become sticky when the weather is hot, and in some case they completely stick to another surface, to the point that you cannot unstick it without ripping appart the image it was supposed to protect
Second, if you do find a brand that seems to work and that wont get sticky, I would only apply a very thin coat, and only on small patches, where the card needs it the most.
A transparent acrylic paint would probably work the same, with the same precautions to be taken beforehand (there are transparent glittery paints.... you could still see the card underneath)
I am not sure this is a good advice to give, because I am not sure if the result would be satisfactory, or would be even worse than the present situation.
But it might be worth exploring, as long as you try it on some paper before using on the cards ?