Joe Sinnott fortuitously began inking Kirby on The Fantastic Four in late 1965, right when the King embarked on what is arguably the greatest phase of his long career, the full flowering of his creative dynamism exploding the Marvel Universe. Coincidentally during this fertile period, Kirby also developed the many artistic tropes and stylized delineations of speed, power, and energy (“Kirby Krackle”) that have since become graphic standards for generations of comic artists.

Sinnott was there to ink and codify it all, giving Kirby’s complex and sprawling pencils a sensitive, flexible contour and attention to detail that his FF predecessors, Dick Ayers, Chic Stone and Vince Coletta could never have. They were all too one-dimensional: Ayers too heavyhanded with his brush, Stone too cartoony with his uniformly thick outlines, and Coletta too finelined with his scratchy pen (better suited to Kirby’s Thor work) to give Kirby’s new, multi-dimensional pencils the discriminatingly detailed and time-consuming inking they deserved.

Sinnott had in his inking arsenal what those others didn’t: both a bold brushline that was able to give Kirby’s supersized figures the heft and weight they commanded, as well as a fine penline that seemingly never missed the tiniest of dots in Kirby’s Krackle or a single rivet in the King’s outrageous, outsized technology. Sinnott’s brushline also had a natural thick-thin range to properly finesse Kirby’s true graphic signature, the omnipresent squiggle, found on everything from musculature to machinery, as no other inker had before or since.

Of course, aficionados of Mike Royer’s inking of Kirby at DC Comics in the 1970s might disagree. They claim Royer’s inks were the truest to Kirby’s pencils, and have cited Kirby’s own endorsement of Royer’s work as such. While it is true that Sinnott would often “fix” details of Kirby’s work that Kirby would either overlook or pencil sloppily—like crooked eyeballs or costume details—Royer’s more so-called “faithful” inking indirectly exposed a harsher aspect of Kirby’s pencils, a rough-hewn quality that, in its uniformity of rendering by Royer, lacked depth from foreground to background. Nevertheless, Royer has his adherents, and, while such a subjective argument can never be settled, I maintain Sinnott to be Kirby’s greatest inker.

And if Kirby is indeed the greatest penciller in comic book history, and his FF work his greatest single body of work, then Joe Sinnott can justifiably stake a claim as the greatest inker in the history of the medium.