1990 Topps #336 Ken Griffey, Jr (double print)

[bnorth]

Originally Posted by glbills

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My guess is still print offset. With black it uses less ink to do 2 thin layers than one thick layer. As example then you look at the 1986 Roger Clemens Blue Streak error. They printed blue under the black to save on ink. One of the coolest examples is the 1989 Fleer Bill Ripken FF card. If you can find one of the rare print offset cards you can clearly see they printed all 3 colors under the black on the F*ck Face on the bat knob.

No idea how they actually printed the backs on that card, just my guess.