(11-12-2019, 08:35 AM)Marinocollector Wrote: That's how these cards were made. Back in the day, manufacturers would make multiple print runs to keep up with demand. Upper Deck ran out of their 1991 holofoil, and rather than wait for more 1991 holofoil, they used up some of the old 1990 holofoil they had in stock. Eventually, they switched back to the 1991 and then switch to the "Diamond" logo for series 2 and factory sets.
I agree they were print to demand but have not seen any Heroes, SP-1 or SP-2 with 1992 holo. Too bad the 1990 holo variation hasn't caught on. It might breathe some life back into this set. Same with 1991 UD Baseball holo variations.