[Eric72]

I have always avoided card savers (semi-rigids) for this reason. It seems, at least to me, they’ll exert an uneven amount of pressure on the card. They’re keeping the card in place. I believe pressure, and maybe some non-zero amount of friction, are the only forces acting upon the card to do this. That pressure would be greatest at the edges and corners, no?

The impact on the card is probably minimal. Still, I greatly prefer penny sleeves and top loaders.