Kenner altered their packaging scheme slightly for the 3rd series figures. All 1st and 2nd series cards featured a free mini comic, however this bonus was dropped for the 1986 figure shipment. The 3rd series cards exhibited offerless fronts affording an uninhibited view of the character's packaging artwork. The artwork behind the figure bubble, blocked on earlier series cards by the mini comic, was also removed. These changes resulted in the most visually appealing card front from my perspective. Obviously all characters introduced for the 3rd series are found solely on 3rd series cards.
Of particular interest to collectors are the early figures that were rereleased on the final series cards. Based on my experience, it does not appear that all 1st and 2nd series characters were shipped on 3rd series cards. The existence of 3rd series proof cards for all 33 characters illustrates every character was planned for eventual release on a 3rd series cardback. From series one, a sufficient number of Superman, Robin, Wonder Woman, and Batman have shown up from various dealers that I feel it is safe indicating these characters were shipped to stores during the final wave. Wonder Woman and Robin tend to show up with greater frequency than Batman and Superman. From series two, Green Arrow, Darkseid, Steppenwolf, Kalibak, Firestorm, Red Tornado, Desaad, and Parademon exist warranting their released status. I can personally attest to purchasing 3rd series carded Darkseid's at close-out in Kay-Bee Toy Stores during the late 80's. Darkseid and Steppenwolf appear to be the most common of these eight second series characters, although Green Arrow does pop up from time to time. Firestorm, Red Tornado, and Parademon are considered the three most difficult to locate from all of the re-releases. At one point Firestorm was considered the rarest, then Red Tornado surfaced and stole the crown, and finally two examples of Parademon surfaced giving Parademon the designation of rarest. So, the complete re-release 33-Back set currently consists of twelce characters.
What you will find in the chart below is the collection of early series characters on 3rd series cards, which I have assembled from the 2001-2008 timeframe. Many of these are prototype carded samples with hand applied bubbles, which surfaced from a variety of Kenner sources. These samples were primarily used for internal presentations and many possess velcro tabs on the back. These velcro tabs provided a method of hanging during presentations. Each character is distinguished as production or carded sample in the following chart. It is possible that some characters shown in carded sample form were released in production carded form, however at this time I have no photographic documentation to support the release of any characters that are not noted as production in the card type column. My quest shall continue until I find each of the 33 figures in some 3rd series carded form. This may be an unaccomplishable task, but as we all know, the thrill of collecting certainly lies in the hunt!