>>46688182I honestly wouldn't bother with BGS myself unless I was able to look at my card with a jeweller's loupe to make sure the print is perfect. Usually the grades come down on the corners and centering so I reckon the use some sort of micrometer or a device to make sure the borders are uniform to within 0.5mm or something.
No idea because no-one knows exactly what tools or techniques they use to evaluate cards.
