Teflon Circles are large enough to cover the coin face, edge to edge and not just inside a shell.
That being said, the discs are not perfect circles. I thought they were “punched” into perfect
circles, but they quite imperfect which means trimming is a must.
My suggestion: place your
Coin / Shell on the disc and use a fine point sharpie and trim the excess imperfections with
scissors. For shells cut slightly inside the sharpie line.
Tango would help everyone if they
came “square” allowing ample marking and trimming (plus its gotta be easier for Tango too and less
trash to disposal).