I haven't owned a 1989 Fleer Jeff Treadway "w/ Target" version in over 20 years. That changed last week with this most recent pickup. I like the addition of two horizontal print alignment marks on the upper corners. Something different! Off centered top to bottom (in this example) is a plus!
The 'Target' is a print registration or alignment mark used for one of the colors (blue/cyan) in the process. Obviously, something got messed up and the symbol wasn't removed before printing. Probably just a quality control issue at Fleer (surprise!). These 'error' cards were actually a mid to late print run defect and not an early 'error' issue - like the FF or Randy Johnson cards.
