Back in 1991, Topps published a quarterly magazine called "Topps Magazine". It had articles about baseball and Topps baseball cards. It might have started in 1990 and might have run past 1991, I don't remember. The magazines were about the size of your average comic book and had "FREE BASEBALL CARDS INSIDE".
Here are the Fall and Winter issue covers.
In some issues, they featured an original card design.