After this, Sinnott began his long and celebrated stint on a Marvel flagship title, "Fantastic Four", inking Kirby on "The Gentleman's Name Is Gorgon! or What a Way to Spend a Honeymoon!" in issue #44 (Nov. 1965). He remained on the series through Kirby's departure after issue #102 (Sept. 1970)—having contributed visually to the introductions of Lee/Kirby's Galactus, the Silver Surfer, the Black Panther, the Inhumans, Adam Warlock and other characters—and continued on through 1981, missing an issue here and there or simply inking the cover. He made a brief return in the late 1980s. His post-Kirby pencilers included John Romita, John Buscema, Bill Sienkiewicz, Rich Buckler, and George Pérez.