Ken, introduced by Mattel in 1961 as Barbie's steady boyfriend, has gone through many incarnations over the decades. Ken was created just two years after Barbie and has been produced every year since, except in 1968 when Mattel decided to change his body mold. Today's Ken still uses the 1968 body mold, so collectors use the stamp on the back of each head mold to determine the era in which the doll was made.

There are approximately 247 versions of Ken, from clean-cut sailor to beach bum to Olympic gold medalist. Ken's vintage era is characterized by elegant, boy-next-door attire. His clothing is scaled down perfectly and even includes working buttons and zippers. During Ken's mod era, his clothing became more unique and vibrantly-colored.

In addition to the standard Ken dolls, a few collector Kens have been produced, such as the Wizard of Oz series and Hollywood Legends. The first Ken doll specifically made for co...llectors was the Hollywood Legends Ken as Rhett Butler in 1994. Dress Box Kens are the most valuable and hard-to-find Ken dolls. They were released between 1963 and '65 and there are 14 different versions in the series.