Recently I purchased several direct fit airtites (no rings) and have noticed that a few high areas actually touch the surface of the airtite. With Morgans its the hair above the ear and on Franklin's the areas that touch are the cheek, hair behind the ear, and letter "D" in GOD. Obviously the coins do not move, but my question is do you think this pressure can affect the areas in contact if movement doesn't occur? The coins used are MS63-64.
I don't like the direct fit airtites for exactly that reason. I know it shouldn't matter, but it bothers me so I use the black ring airtites. Even if there is no friction, there appears to be pressure.
I use the black rings also, and the bonus is they really set off copper, looks great as well as safe !!