I might try some cards with close-ups of small areas rather than shrinking the whole image down to fit the front of a greetings card.
I reckon this first one might be a reduction too far (borderline indecipherability), the psychic blackboard pieces seem to work better printed very large, probably due to being scanned at 600dpi:
Tried a wraparound idea with this next one, but not entirely sure it works. Again, it might be better to do a close-ups on a square card rather than a wraparound on a rectangular one:
(Note to self- they don't ALL have to be reproduced as greetings cards)