Director and screenwriter Brad Bird always took issue with one comic-book trope. Were we really to believe that Peter Parker was bent over a sewing machine, whipping up his Spidey suit?

So for “The Incredibles,” his 2004 Pixar flick, he found a far more plausible situation: Bird’s superheroes turned to a costume designer who made her name crafting customwear for the gifted. Edna Mode, with her acerbic one-liners spit from a pint-size frame, was an instant fan favorite. Featured only briefly in the movie, she made enough of an impact to be asked to present the 2005 Best Costume Design Oscar alongside Pierce Brosnan (and a little TV magic).

In “Incredibles 2,” out Friday, the legendary designer is back, dahling. Audiences will see her special skills at work once again as she creates a personalized outfit for baby Jack-Jack, whose powers have come to fruition. Spoiler alert: no capes!

For 14 years, fans have speculated about which real-life person Edna is based on — eight-time Oscar-winning costume designer Edith Head and Comme des Garçons founder Rei Kawakubo are two popular theories. But Bird says there’s no truth to the rumors.

“The funny thing is that when I was promoting the first film all over the world, she was the only character everyone was convinced was based on someone from their country,” he tells The Post.

One thing Bird always imagined, however, is that Edna is half-German and half-Japanese.

“Those are both relatively small countries that have sort of an enormous impact [and] outstanding technical products coming from them,” he says. “That’s what she is: a compact person with a very large personality and influence.”

Bryn Imagire — who as the shading art director was responsible for the colors and textures of characters, props and sets — says that over in the art department, Head was indeed a visual inspiration for Edna’s distinctive look, given the blunt bangs and bold, circular-framed glasses.

For the sequel, Imagire was tasked with creating two outfits for Edna. Incorporating the character’s heritage, she referenced the work of Japanese designers Kawakubo, Eiko Ishioka and Sacai’s Chitose Abe.

“Rei Kawakubo has a quote … ‘For something to be beautiful, it doesn’t have to be pretty,’” Imagire says. “So I took that and started to think about Edna’s costumes not as pieces of clothing, but more as abstract sculpture.”

Imagire designed roughly 25 looks, and showed 15 to Bird. The final two that made it into the film are a sophisticatedly simple indigo dress and a black-and-red kimono.

As much as Edna’s known for her style, she’s also known for that voice — one that Bird describes as a “mishmash” of Japanese and German accents, with a whole lot of attitude.

Pixar films begin by temporarily casting characters internally for what’s known as “scratch voices,” and so for the first movie, Bird initially provided the voice for Edna, in addition to those of leading character Bob Parr and the villainous Syndrome during production. He then approached Lily Tomlin about taking on the role of Edna and recorded the entire part into a tape recorder for her to listen to. A week later, Tomlin told Bird she thought he should just do the voice himself, and that’s exactly what happened.

And as it turns out, Bird and the fashion diva share more than vocal cords.

“At my most confident, I feel like her,” says Bird. “She is absolutely convinced that her way is the right way, and if you disagree … you’re just wrong!”