Mr Fantastic Invisible Girl Emblem Question

[hedrap]

I don't have Ben's book at hand, so could someone tell me what the material is for the FF emblems? I'm wondering why it was used for Thor's armor and 12" Superman, but not for Iron Man or 12" Cap.

Are they heat sealed to the fabric or glued?

[AAAAA]

heat pressed vinyl
heat pressed was possibly a new technology .when the very first figures were offered
the circles would be easier , stars very hard because you get a spreading (stretching) from the heat and distortion on small areas.
iron mans chest repulor is 3 dimensionall