1999 Topps Crystal
1999 Topps Crystal was a Test Issue for a set that was never produced. The cards have the look and feel of 2000 Topps HD and one can assume that Crystal served as a "test" for HD's printing process. These cards were never formally issued by Topps in the way similar Promos of the era were, and it is unclear how these cards emerged into the secondary market -- probably through the "backdoor."
Every Topps Crystal card that has emerged is serial-numbered "00/99" on the back. It is unclear exactly how many of these cards were printed, however it can be assumed that fewer than 99 copies were printed.
As of 2016, these are the only five 1999 Topps Crystal cards known to exist. Any assistance on identifying previously-unknown 99 Crystal cards would be greatly appreciated.
PP1 Craig Biggio
?? Wally Joyner
?? Ivan Rodriguez
?? Andy Brown
?? Mike Mussina