The 1990 Collect-A-Books set was issued by CMC (Collectors Marketing Corp.) in three different sets (boxes) of 12 players apiece. The sets (boxes) were distinguishable by color, red, yellow, or green. The Collect-A-Books were in the style of the 1970 Topps Comic Book inserts but were much more profesionally made. The cards all fit into a nine-pocket sheet (since they are standard size) even though they can be expanded. The set contains an interesting mixture of retired and current players. The concept for this set was created by former major leaguer Jim Bouton.