Nothing says ’Merica like star-spangled hot pants.

Allison Ditson flips through a stack of her handmade garter shorts and swimwear while Prince’s “I Would Die 4 U” fills her warm attic studio. Fabric is draped over every nook and cranny — in stars and stripes, neons and florals, glittering golds and black mesh — making the cozy space look like the shared dressing room of Wonder Woman, Betty Grable and Katy Perry.

It’s the last day of June and Ditson is preparing for “Summer Strut: A Fat Fashion Show” that will hit the runway at Portland’s White Owl Social Club July 13. She will show six two-piece retro-cut swimsuits featuring patterns from pin-up stripes to sparkling mermaid scales. Ditson, who is transitioning out of ownership of downtown’s Kitsch boutique, has made a full-time business of Allihalla, her line of custom swimwear and lingerie that celebrates the human form whatever the size, shape or sex of a client.

“Swimwear is hard to find to fit because it’s all been standardized,” she says. “For store-bought stuff, I think everybody has a hard time finding it, so I may as well offer something specialized.” While Ditson will make swimsuits to order in any size, she has found a niche in curvy clientele.

“It’s made with this idea that you should feel bad about your body and hide it,” Ditson says of plus-size designs. “That’s a pretty lame message to have behind clothing.”

Ditson, who started sewing in high school, says she has always been interested in body-conscious designs, which led her to focus on lingerie and swimwear. Learning how to work with stretch fabric was key — a skill she learned from her father, Les Ditson.

“My dad was a modern dancer in the ’70s and he made all the costumes,” she says. “A lot of people don’t do stretch stuff. Stretch is like a whole different realm of sewing. Because my dad has the background in dance costumes, he has a lot of information regarding stretch, so it was never a different world of sewing for me.”

Ditson says she also never learned to use traditional patterns, which helps her shift between different body types more fluidly.

“If you’ve been taught through a design school how to pattern on a mannequin, then that’s what you’re going to know how to do,” she says. “So when a body isn’t shaped like that you’re going to have to reset your ideas of how to pattern for that.”

In addition to Summer Strut, Ditson is finishing up custom orders for Oregon Country Fair (a full-body batwing jumpsuit) and patriotic pieces for friends for the Fourth of July.

“The American collection was my favorite line of stuff,” Ditson says. The collection (see cover), which debuted at Eugene Fashion Week a few years back, was one of the most memorable shows in EFW history. Ditson styled her models with corn dogs and big gulps while the crowd chanted “USA, USA.”

And what will Ditson be wearing come Independence Day? Those star-spangled hot pants.

To see more Allihalla designs, visit her Etsy page at http://wkly.ws/1s7.