The Magicard web site lists consumables for the same printer that Rob linked to. They list the ribbons as being "YMCKO". Googling for that reveals:

Quote:
YMCKO = Y = Yellow, M = Magenta, C = Cyan,
K = Black, O = Overlay/Laminate
Yellow, Magenta, Cyan & Black make up a full
colour image whilst "Overlay" adds a
clear varnish on top to prevent the image from rubbing off.