Based on what I know of similar Pinnacle products of the time in the Racing category, it looks to me that the silver foil cards are printed on reflective silver card stock. The difference will be most evident in the black background, the foil one will be somewhat reflective where the base card will be opaque black.
-Tom
Ted Musgrave card collection 98.9% Complete: Cards Known: 1013, Cards Owned: 1002
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