When pushed directly on whether it was Welling’s decision not to suit up in the series finale specifically, the actor was more cagey. “It was literally something that the entire series was behind in not doing that,” Welling says. “We did things on that show where we didn’t call them powers, we called them abilities — you weren’t allowed to say powers; you just weren’t because Clark didn’t know they were powers, he just knew he had those abilities, so little things like kept us grounded and kept us faced onto the story we were telling about this character, not what he could do with these abilities.” The slogan was “No tights, no flights.” for Superman origin story Smallville, which starred Tom Welling as the future Man of Steel struggling to understand his abilities while inching closer to his destiny. Hence, fans waited desperately for the moment Welling would actually suit up, assuming it would happen in the series finale. And it sort of happened. In the closing moments of the final episode, viewers saw Welling’s Clark Kent rip open his button down shirt to see the House of El insignia underneath in an iconic recreation of the comics, but once Superman took flight, it was only shown from a distance via CGI — and for good reason.
Source: Smallville star Tom Welling breaks silence on series finale suit-up