I have two cards and am not sure if they are refractors or not. I cannot tell from looking at them. Someone said, or I read somewhere, that the refractors have a "rainbow." I understand that to mean theat the border, when light is shined on the card, reflects a variety of colors. Is that a fair statement and the legitimate way to determine if a refractor?
Is there any other way, e.g. some serial numbering on he obverse ala the 2015 FHR cards?
Thanks,
Frank
Is there any other way, e.g. some serial numbering on he obverse ala the 2015 FHR cards?
Thanks,
Frank