The 1909-11 baseball T206 set is called "The Monster" for good reason. It's one of the most widely-collected sets of any era. T206 also contains the single most famous card in the hobby, one recognized even by non-collectors. While most cards are easily obtained, the release has some very scarce options that are led by the nearly-mythical Honus Wagner card. This all combines to form a set that can be collected in a wide variety of ways. There is truly something for almost anyone in the T206 baseball set.

The “T206” designation came from Jefferson Burdick in his American Card Catalog in the 1930s, but the cards are also known as "white borders" due to their design. That border surrounds a strikingly colorful lithograph, with simply a last name and city below the picture in black ink. Most of the card fronts are vertically-oriented, but a small number of cards feature a horizontal layout. However, there are a lot of similar white-bordered sets of the era (many of those even using the same pictures), which causes some confusion among collectors.