Early work

Sears's career began in 1985, after completing one year at the Joe Kubert School of Cartoon and Graphic Art. He produced the art for the mini-comic that came with the Sectaurs Skulk and Trancula toy. He also worked on various role-playing game titles, including Gamma World, Marvel Super-Heroes adventure game books 3 & 4 and a few others. He started producing comic art for several smaller companies, including work on Hero Alliance and several dozen covers for Quality Comics. Bart eventually moved over to DC Comics, where he produced work such as pencils on The Spectre #21, a few C.O.P.S. issues and all three covers in addition to interiors to the third issue of the Invasion! series, before becoming regular penciller on Justice League Europe.

Ominous Press and the 1990s

Sears achieved great success during the 1990s. After critically acclaimed runs on Legends of the Dark Knight, X-O Manowar, Turok, and Violator (the last of which was the #1 selling comic of 1994), Bart set up Ominous Press, considered by most fans to be the height of Sears's career, although only three actual comics were produced: It Begins, Mael's Rage, and Infinity, as well as a few other pieces of merchandise.

After Ominous Press closed, Sears returned to X-O Manowar for the Birthquake re-launch. Then moving on to Penthouse Comix and eventually Marvel Comics, where he worked primarily on Blade the Vampire Hunter and Spider-Woman.

Recent years

Sears moved to Tampa, Florida, in 2000 to join the fledgling comic company CrossGen Entertainment (CrossGen). Bart worked on both The First and The Path. During this time, he became assistant art director at CrossGen, and subsequently art director.

After CrossGen's demise, Sears was offered work at several comic companies, but opted for Marvel Comics, where he produced a variety of work, including Captain America and the Falcon, Sabretooth: Open Season and Weapon X: Days of Future Now.

Sears then moved to DC Comics, where he produced work on several things, but most notably the relaunch of Warlord.

Sears then went freelance again, before landing at Dark Horse Comics, where he produced work for The Scream and The Helm.

As of December 2008, Sears has moved away from the comics industry for the first time in over twenty years, working for gaming company Heatwave Interactive, based in Austin, Texas, where he is their senior concept artist.