Grading companies marking cards.
 

With the issues that are in the hobby right now, how would you feel about grading companies putting a substance like invisible ink on the cards? Would the grading companies have to tell you that they possibly could do that to your submission? I personally wouldn’t like it, to me the card is no longer original.

No way !

PSA supposedly does that on all signed items they deem authentic.

Or they could just actually catch alterations?

Identifying antiques by altering them first is a bad idea.

marking cards
 

There was a big time dealer in the Cleveland area back in the 1980s that stamped all his cards with invisible ink on the back in an effort to catch shoplifters. I always thought it was a bad idea in that who knows what that ink would do to the card in 10 or 20 years If any of you bought a card from him and still have it...... put a black light on the back and see !!! I have edited my post to delete the name as I am not sure if he did all his cards this way or just the big ones .... my time seeing this was between 1982 and 1985.

I'm not sure why you would bring up invisible ink, which may have been state-of-the-art in the 1950's, but is hardly a candidate for use now. But, I think the TPGs will have to come up with a reliable/affordable approach to ear-marking every card as it is graded so that it can never be submitted for grading again without being identified. If that can be done by just saving digital images and training a computer to check each card against the data base, good. But if it requires the insertion of a permanent marker in the card, collectors will have to accept that approach as the lesser evil. If it turns out invisible ink is best, so be it. Not the way to bet though, IMO.