While searching eBay, I found a whole slew of 1990 Donruss Blue/White Test cards as well as 1990 Donruss Aqueous cards. However, I also found a new test card that is a hybrid of both the Blue/White and Aqueous cards. These cards are currently not cataloged anywhere and feature a glossy red front and a non-glossy red back. This is similar to the Aqueous cards in that the front is red and glossy, but they are also similar to the Blue/White cards since they feature a player on both sides with one side glossy and the other side non-glossy. I have cataloged all the cards I could find on eBay in this checklist. These test cards appear to cover roughly #350-400 in the set.